[TASK] Improve classLoader compatibility for Windows systems

On Windows systems the (absolute) paths are different to unix ones. The
core already provides functions to catch both cases in different checks.
This patch enables the use of those functions in classLoader.

Resolves: #52774
Releases: 6.2
Change-Id: I7dd4b2f7a88b07281222995a58962deeb27e8869
Reviewed-on: https://review.typo3.org/24722
Reviewed-by: Wouter Wolters
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers
Reviewed-by: Jigal van Hemert
Tested-by: Jigal van Hemert
Reviewed-by: Nicole Cordes
Tested-by: Nicole Cordes