[FEATURE] Replace FAL signals with new PSR-14 events

All FAL-related signals are migrated to PSR-14 compatible Events.

Existing signals are moved to a compatibility class, so they are still
executed without throwing a deprecation.

This change allows to further decouple EXT:core from other system
extensions (in this case Extbase).

Resolves: #89577
Releases: master
Change-Id: I062c7261de9a0e21140346c1934e9c735fd5b307
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61715


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Frank Nägler <frank.naegler@typo3.org>
Tested-by: Susanne Moog <look@susi.dev>
Reviewed-by: Frank Nägler <frank.naegler@typo3.org>
Reviewed-by: Susanne Moog <look@susi.dev>