[TASK] Extract url generation in ext:workspaces

Patch extracts generating url for workspaces
in order to better integrate with external extensions,
so when external extension want to replace url,
extension does not have to override whole handleRequest method.

Resolves: #98112
Releases: main, 11.5
Change-Id: I8c8e18fbe7dfecd2ccd400681588d984ac233178
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75367


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Benni Mack <benni@typo3.org>