[SECURITY] Mitigate timing discrepancies during user authentication

Observing response time during user authentication can be used to
distinguish between existing and non-existing user accounts. This
change introduces `MimicServiceInterface::mimicAuthUser` -  to be
implemented by 3rd party authentication services - which simulates
corresponding times regular processing would usually take.

Resolves: #98217
Releases: main, 11.5, 10.4
Change-Id: I143ae0d3877dffe6f2decbb3f0cf8c9d9cb6ca0b
Security-Bulletin: TYPO3-CORE-SA-2022-007
Security-References: CVE-2022-36105
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75710


Tested-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>