[TASK] Remove Environment::getFrameworkBasePath where easily possible

Environment::getFrameworkBasePath() API was created
under the assumption that TYPO3 core extensions are always installed
in a dedicated but fixed folder (typo3/sysext).

Additionally this folder is assumed to be publicly accessible
through a web server.

Therefore this API is used in two contexts.
1. To resolve and check file system paths
2. To create URLs to public resources

To at some point achieve the goal to allow all TYPO3 extensions
to be installed in arbitrary locations (a configurable
vendor folder), usage of such API must be removed.

As a first step all usages are removed, that reference
files within the boundaries of one extensions.
Relative paths (relative to the file that references) are used
instead, or, where possible EXT: syntax

Releases: master
Resolves: #95250

Change-Id: Ie7291b71d5d85d75add9bc5b352a4bd1cf065499
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71102


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Helmut Hummel <typo3@helhum.io>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Helmut Hummel <typo3@helhum.io>