[TAKS][CONF] Accept other settings in [SYS][setDBinit]

Since the mysqli interface recommends setting the charset using the
mysqli API the utf8 charset will be initialized when establishing the
database connection using mysqli_set_charset().

Additionally [SYS][setDBinit] can now be set to any value or can totally
be removed. To make sure the database connection still uses the utf8
encoding an additional check is added to the bootstrap process that
checks the MySQL character set session variables.

Finally the old default value of [SYS][setDBinit] will automatically be
removed if it is set to the old default value.

Resolves: #41596
Releases: 6.2
Change-Id: I8d0a9eba50495d52accb59627147c1c87b6a9bb5
[BUGFIX] Correct file language overlay for pages

This patch corrects the fields the FILES content object is using for
doing the language overlay for file references for fields in the pages
table.

Instead of the _LOCALIZED_UID that is only available for other record
types the _PAGES_OVERLAY_UID field is now used to check if there
is a translated version available.

Resolves: #47869
Releases: 6.2, 6.1, 6.0
Change-Id: I2465a9e3ccd49223cc44885ffba8484788e1b669
[BUGFIX] Correct handling of empty Backend Layouts

Since the default value of the page properties backend_layout and
backend_layout_next_level is an empty string the value in the select
item is changed from zero to an empty string for consistency.

Additionally the BackendLayoutView will treat an empty string equally
as a zero namely as a non set Backend Layout.

Resolves: #52596
Releases: 6.2
Change-Id: Ic792f748d005f5749f24a3e979b304c23320c8fa
[FEATURE] Make getPlaceholderValue recursive for __row

If __row|uid_foreign|field is a reference its not evaluated
recursive the placeholder shows a uid. With this patch the
content of the field is shown.

Additonally the type of the metadata field of sys_file was changed
to inline because select does not support the foreign_field property.

Resolves: #52630
Releases: 6.2
Change-Id: Iee30274d2e94f73e877b761d119801bb205689c1
[TASK] Reusable getCategoryFieldsForTable itemsProcFunc

Allow the usage of the method
\TYPO3\CMS\Core\Category\CategoryRegistry->getCategoryFieldsForTable
that can be used as itemsProcFunc for select fields in the TCA in
multiple context by introducing a new categorizedTable configuration key
in the config section of a column in the TCA.

This configuration key can either consist of a single string containing
the name of the table or a configuration array to define additional
conditions that need to be true so that a configured table is used.

Resolves: #53045
Releases: 6.2
Change-Id: I128cbeb6747a8f83e68cdaaaafbc3ab5901353d4
[BUGFIX] Followup Fluid Template Fallback paths

In the previously merged patch are some glitches and a regression:
- The usage (and test for existence) of deprecated functions has been
  removed.
- The value passed by the old behaviour overrides the new one
- The typo preventing usage setLayoutPaths() has been removed.

Intended usage:
plugin.tx_a.view.templateRootPaths{
	extendedA = <some additional path>
	default = <some default path>
}
The first hit will be used as template.
In case only numeric indizes are used, the entries get ordered.
See unit tests for a more specific description.

Change-Id: If4fa75347614cf9b352c6016430a928833cc62cd
Resolves: #52971
Releases: 6.2
[TASK] Unify data for jump URL hash generation

The jump URL generation is unified and moved to a new JumpUrlUtility
class. All methods in the ContentObjectRenderer are now using the same
method for creating jump URLs.

The handling of file and directory names with special characters is
improved and FAL file records with special characters in their file names
will also be URL encoded.

Additionally Unit Tests are added to verify the jump URL function.

Resolves: #52156
Releases: 6.2
Change-Id: I7d2d8cec005aae56a118850071ca669ef9740c9d