When using checkPythonSourceCode integrated in the source code editor,
for a scenario where developer edit a component and save we can benefit
from caching the check message for the source code content, because the
same check that the one happening in the editor will happen when the
component is saved.

This cache varies on:
 - "component_packages" cache cookie which is reset every time some
component code is edited.
 - zope startup time to take into account editions of file system code.
This assumes that after reseting file system code zope will be
restarted.
 - portal_type, because the checks performed by this function also
depend on portal type.

this makes completions works when using Ctrl+space

This makes "Format Document" / "Format Selection" work.

because pylint is a bit slow on large components, debounce every 2
seconds. TODO: this is too slow.

For now this is just the portal_url, but I'm thinking it could be a
proper tool.

IIRC the only thing needed is that ERP5TypeTestCase.getPortal is an
ERP5Site

on very large python files (>1000 lines) sometimes they queue up and we
have to wait for all requests that were queued by zope.

XXX maybe this does not happen when accessing through haproxy/apache, I
am observing this when hitting zope directly

because title is acquire from id, we want to edit title first for the
case where we change ID, otherwise saving would save the old ID as
title.

 * don't set "hide rows on no search criterion", this should not display
too much and search is broken.
 * use preference to get number of lines

So that it can be registered properly on load and later added through the ZMI.

ZODB Components: Tool Component: Only validated 'reference' must be considered when registering a Tool.

Otherwise setting an invalid reference will make the Component 'modified' but
try to use that invalid reference to register it and fail.

With chrome ( 85.0.4183.108 but I think it appears a few weeks/months ago )
when using erp5_xhtml_style when the cursor in the first column on the left
it's not visible, because the bold background hides it.

Default user agent spreadsheet is a 2px padding, but we have a rule applying a
padding 0 for all textarea. Revert this rule for textarea used as fields in
content.


---

## before:

The cursor is in *Description* field, left to "This style is ..." but cannot be seen.

![image](/uploads/f40262af196d799291643604b91ae2c4/image.png)


## after:

The cursor is same location (*Description* field, left to "This style is ...") and this time is visible.

![image](/uploads/bf1ec63532e2eca1fca7655a4581935a/image.png)

See merge request nexedi/erp5!1280

See merge request nexedi/erp5!1282

Previously this would be rendered as empty String
(unless we had a hidden field to define precision)

Commit adds also testListboxZeroValue in  erp5_web_renderjs_ui_test

See merge request nexedi/erp5!1173