[FEATURE] Add BeforeLoadedPageTsConfigEvent

With the recent deprecation of adding page TSconfig via ext_localconf
as a string, the need for a new PSR-14 event arose. This event can be
used to add global static page TSconfig before the global page.tsconfig
files are loaded. This allows extensions to add basic config, which
still can be overridden with page.tsconfig.

Resolves: #101818
Releases: main
Change-Id: Ic6fc0bff5e19c6c097c123386452b0e2bba0e17e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80814


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>