[TASK] Streamline providing CSP mutations

The new MutationRepository is a central place for providing
static mutations (from configuration) and resolved mutations
(static mutations + dynamic resolutions from database). The
corresponding logic has been extracted and moved from the
PolicyProvider to the new repository.

Resolves: #102011
Releases: main, 12.4
Change-Id: Iaa627236fd55fb2c7c910ea7c13b54a1ad7cc663
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/81174


Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>