[BUGFIX] Return PSR-7 responses in EXT:extensionmanager

Since #92784, all extbase actions are required to return
a PSR-7 response interface. Because the controllers in
EXT:extensionmanager were not adjusted, this triggered
a lot of deprecation log entries recently.

Therefore, all extbase actions in EXT:extensionmanager,
which do not just redirect to another action, now return
a proper PSR-7 response.

Resolves: #94178
Releases: master
Change-Id: Ideb142215647bad5c04decb5f1f1e24003aa14d0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69220


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>