Feature: #94623 - tt_content images, assets, media showPossibleLocalizationRecords

See forge#94623


When a default language content element is localized to another language in "connected" / "translation" mode (as opposed to "copy"), relations like images and assets connected to the default language record are localized as well.

When the default language element is later changed and additional images, assets or media relations are added, the localized content element now shows those new default language relations as shadowed box and allows to localize them with one click.


This is a usability improvement for editors, who now see which tt_content relations of casual elements like "Image" and "Media" are missing when editing localizations. They can localize those with one click.