ZODB Components: erp5_trade: Migrate TestOrder{Mixin} and all Unit Tests inheriting from these classes.

Also, Split testInvoice to a Module Component in erp5_invoicing for Mixins used
by several other tests and Test Component in erp5_simplified_invoicing (initially
everything was migrated to erp5_invoicing but this does not work as Alarm_buildInvoice
is different in simplified and advanced invoicing).

efd71291 added on erp5_invoicing a test dependency on erp5_advanced_invoicing.
However, testRule for example uses erp5_invoicing but not erp5_advanced_invoicing
so this would not work.

Moreover, erp5_{simplified,advanced}_invoicing enhance erp5_invoicing by providing
a container for Invoice Line so to match real world use cases it is better to
have two CodingStyle tests: one checking erp5_invoicing+erp5_simplified_invoicing
and the other one erp5_invoicing+erp5_advanced_invoicing.

Also, fix CodingStyle issues on erp5_advanced_invoicing.

See merge request nexedi/erp5!1243

padding too much in buttom make header bigger, so when export to pdf, header is cut off to hit heigth which make logo display at top

also needs to be declared in hidden content types to prevent adding
directly in preferences

should be same for cases where type based method is a python script, but
is a bit more explicit/safe and consistent with other usages.

In 93e30e5e (Person: Store user id in new user_id property., 2016-12-09)
we adapted this test to the new behavior: title fallback to user_id or
id, but since persons always have a user_id by default, this test was
changed to check that title fallbacks to user_id, but the name of the
test still mention "fallback to id" which became a bit different from
what was tested here.

Revert testEmptyTitleFallbackOnId to check that title fallbacks on id,
using persons without user id and introduce new
testEmptyTitleFallbackOnUserId to describe the new behaviour with user
id.

See merge request nexedi/erp5!1244