This backports parts of zope commit bb7837c66 (Explicitly make all
classes new-style., 2017-09-15) and 173658008 (Fix unpickling of instances
those base class changed to a new-style class. (#208), 2017-10-24),
so that business template is same between zope4 and zope2 and so that
business templates created with zope4 can still be installed on zope2.

re-exporting a business template that was just installed should not be
different.

By having a test reporting diffs in export, we can detect changes in ERP5 or
dependencies which would cause the business template format to become different.
The primary reason for doing this was to make sure that on the way to Zope4 we
don't have changes in exported data, especially lossly changes that would not
be detected in test suite, but this is also good because it helps detecting
changes that cause a difference in output - then if we introduce a change that
cause different business template export, we also have to make a change to
re-export everything to new format, which helps keeping the git history cleaner
because there's one big commit with all the changes instead of having many small
commits. This is also good because it detects mistakes when modifying business
templates files directly with a text editor.

The test can be configured to ignore some paths, using fnmatch pattern (which
unlike business patterns do not support ** for recursive match). This is also
helpful when using this test case to check customer configuration business
templates, where we may want to ignore some PathTemplateItem for convenience.

Workflows chains are not exported like this, maybe this was exported
with some patches to BusinessTemplate.py

maybe something was wrong with 3125451e (*: Update XML to new
WorkflowHistoryList data structure, 2020-06-12)

The data model changed in 3b0e01ed (pdm: support defining price in
another quantity unit, 2020-07-07)

since a282fc24 (ZODB Components: Do not export some Workflow History
fields., 2014-02-24) these are no longer exported

We now only have the expression "source" not the compiled expression
instance

follow up of 1ca655a3 (Optimize WorkflowHistoryList, 2019-09-24)

This is now exported by business templates

These should anyway probably be exported as normal portal types

Since 36cd50f5 (Remove 'last_id' from exported BT items, 2011-10-13),
these are no longer exported.

These were probably edited directly with a text editor, because some
details are different

Avoid repeating processing_node condition for every single activity
whose serialization_tag dependency is being checked. This reduces the
length and execution complexity of produced SQL.

The meaning of empty items for **multi** list fields for categories is
not clear for dialogs (if user does not want to apply any filter, then
the natural way would be to select nothing).

This also caused issues with category fields, when the action script
uses restrictedTraverse to get the uids corresponding to the category
but a path is empty, like for example in 
https://lab.nexedi.com/nexedi/erp5/blob/d51bb0413a806b3db0c5eb69dec06065b9601322/bt5/erp5_accounting/SkinTemplateItem/portal_skins/erp5_accounting/AccountModule_getTrialBalanceReportSectionList.py#L40-48

which does this:

```python
# optional GAP filter
node_uid = []
gap_uid_list = []
for gap in request.get('gap_list', ()):
  gap_uid_list.append(portal.portal_categories.gap.restrictedTraverse(gap).getUid())
if gap_uid_list:
  node_uid = [x.uid for x in portal.portal_catalog(
                                   portal_type='Account',
                                   default_gap_uid=gap_uid_list)] or -1
```

If an empty item is selected, then `gap_uid_list` will contain an entry for 
`portal.portal_categories.gap.restrictedTraverse('').getUid()` which will be the
uid of the gap base category. Searching with a base category uid nowadays does not
match any document, but before 95e3eaec (CMFCategory: Do not index any Base Category
as a related document., 2016-12-21), it was matching all documents having a relation
from this base category and in the case of this trial balance report it was matching all
accounts.

This was a problem for old instances with accounts created before 95e3eaec, because when
they were first indexed, they had the record in category table, so they were matched, but
once they get re-indexed, they no longer had the record, so the result of this report when
selecting the empty item became different, because accounts were no longer included.

Looking back at this, maybe when updating to get 95e3eaec, we should have ran a migration
to delete all these records (re-indexing every document in the background should be enough)
so that if there's a problem, the problem happens right now and not after a few months
after accounts are modified and re-indexed.

When looking at this from end user level, theses empty items not only cause this problem,
but also does not have a clear behaviour and are not needed, so the changes here are about
removing these empty items.

In accounting reports, there was a multi listfield showing all gap categories, "grouped" by
chart of account - but the name of the chart of account was not displayed. This change to
use a None item, which is rendered as disabled to display the chart of account name, but to
do this we had to fix a bug in Formulator, these disabled items were only working properly
for single item widgets, not multiple items widgets.

See merge request !1572

This addresses a regression from !1561 changing the class hierarchy caused Login to loose its docstring and became no longer publishable.

This was problematic because it was not detected by the test suite, so HTML test is changed to use zope publication instead of calling the view on the context.

Another notable point is that this behaves differently in ERP5JS, the Logins were still visible in ERP5JS. Because we don't actually rely on "no docstring on the class" to prevent publication, this is not changed.

See merge request !1571

There was opening and closing tags mismatch:
    <div><a href="#references1_anchor">References</div></a>

This seems to be used only in Localizer's ZMI. This is not compatible
with newer version of DocumentTemplate, but because we don't use, it's
better to remove the functionality

In order to stabilise UI tests which are waiting for the loading animation
to play during language change.
Pick a small delay so users should not notice (value suggested by Romain).

When we have more than one language and many documents with same reference but with different language, the first impression is that we have many duplicated documents.

Display the language, we can easily detect that we have same reference to different languages.

While in a "single" list field, we need an empty item that will be
selected by default, there's no such need on a multi list field.

These empty items also have the problem that their meaning is not
really clear.

Instead of having empty string items which for which the meaning is not
really clear.

processing_node -3 is not automatically used anymore, such failure would
nowadays be a processing_node of -2. So simplify this comment.

For example, an immediateReindexObject and a
SQLCatalog_deferFullTextIndexActivity may be spawned.

Without this, more categories than can be displayed in the dropdown menu
may match, pushing expected "Quantity" one out of the list, causing the
test to fail.

This is more realistic, because a real HTTP request will use
ZPublisher.BaseRequest.BaseRequest.traverse, which has slightly
different behaviour than getting the form on the context of document.

The behavior becomes different for documents which do some logic on
traversal (like for example the web sites changing the skin).

This was breaking for cases where values contained characters used for
markup such as <> or & and also for the special case of None which is
used to render disabled items.

Zope only publish objects if they have a docstring. The change in class
hierarchy from b7a60478 (ERP5Security,erp5: simplify
EncryptedPasswordMixin.setPassword, 2022-02-21) caused that Login and
subclasses no longer have a docstring and as a result there were no
longer publishable by Zope, so it was not possible to view them in xhtml
style. ERP5JS was not affected, because it does not directly rely on Zope
publication APIs.

We don't want to use wildcard in core business template, because when
another business template extend these paths with new documents, the
new documents are included in erp5_core.

This also cause issues for tests creating dummy content in these paths.

This was still working with Zope 2.13 because the default output_encoding for
HTML was iso-8859-15 but this is not the case anymore with Zope 4. Moreover this
should be explicit rather than implicit anyway...

Revert "testBusinessTemplateTwoFileExport: Make output_encoding explicit as it should have always been."

This reverts commit 968991e7 which does not
actually work properly with Zope4.