[TASK] Consistently limit scope in FilesControlContainer

Since we are in the scope of a web component,
access to "document" is now consistently avoided.

Resolves: #100814
Releases: main, 12.4
Change-Id: I38b0b9f1796a3ff512bbf62bd518105cbaf273b0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78946


Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78962