[TASK] Organize file / link selector output

This change sorts out the link selector fields and
additional fields, as well as the file selector to streamline
the padding/margin between all boxes, cleans up the search box
and adds some UX improvements to make the modal less cluttered.

Some labels still need to be moved to a XLF file.

In addition, some minor PHP cleanups are made to make
the dependencies more visible.

Resolves: #93322
Releases: master
Change-Id: I5f191cefbf1e1fd8dae9e398d3001faf72193cb5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/67467


Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Richard Haeser <richard@richardhaeser.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Richard Haeser <richard@richardhaeser.com>