[BUGFIX] Allow to modify redirectUrl via PSR-14 event in EXT:felogin

The "BeforeRedirectEvent" in EXT:felogin did not
allow to modify the actual redirectUrl,
which is now modified, as the Event was not
as powerful.

Resolves: #96813
Releases: main, 11.5
Change-Id: I5716c9a3f8d58cd019dca5e3e9d47a242c9ec45e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78059


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>