[TASK] Windows issues with long file names in Git sources

The recent DataHander functional tests integrate file names that
are very long since they contain a description of what actually
is expected in the accordant test assertion file.

However, Windows has a limit of 260 characters per file path.
The longest file path of the mentioned functional tests has been
223 characters and is now reduced to 166 characters.

Resolves: #56177
Releases: 6.2
Change-Id: I1490a3f0fae7ef40547d81e304cb98077ab6142b
Reviewed-on: https://review.typo3.org/27815
Reviewed-by: Marc Bastian Heinrichs
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader