Scenario:
A tt_content default language record with images, assets or media
is localized ("translate" / "connected" mode, not "copy") to
another language. Attached images, assets and media will be
localized, too.

If later the default language record is changed to add another
image, asset or media, the localized record now shows the
additional default language record relation as shadowed box
and allows localizing this additional record with a single click.

This is done by setting for those TCA inline relations:
['appearance']['showPossibleLocalizationRecords'].

Notes:
* showPossibleLocalizationRecords works on l10n_parent and does NOT
  honor l10n_source (yet?): In a 'localization chain' (default is
  localized to dutch, dutch is localized to german), an additional
  image, asset or media on the dutch record *is not* shown in the
  german record, but an additional record in default language *is*
  shown in the german record.
* showAllLocalizationLink: This is an optional additional button to
  localize all missing relations with one click, not only single
  ones. This is *not* enabled with the patch: The additional button
  bloats the already pretty complex interface even more, and editors
  often only need to deal with one or at least only a small list of
  additional relations. Instances where editors often deal with lots
  of such inline relations can easily enable that button on their own.
* showSynchronizationLink: The behavior of that button is in practice
  very similar to showAllLocalizationLink and *not* enabled for similar
  reasons.

Change-Id: I34e469171ac34b06ff0350e8e3725188f6de625b
Resolves: #94623
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70058


Tested-by: core-ci <typo3@b13.com>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>