[BUGFIX] Do not append a "/" to the folder identifier

[BUGFIX] Do not append a "/" to the folder identifier

When creating a folder object the identifier is suffixed with a '/'
automatically which does not make sense when using a non hierarchical
filesystem.
The identifier must not be modified by the Folder constructor.

Resolves: #66861
Related: #65305
Releases: master, 7.6
Change-Id: I9b02767d124a7502f4170cb39a7df3dcff27fe3c
Reviewed-on: https://review.typo3.org/47749
Reviewed-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Tested-by: Jigal van Hemert <jigal.van.hemert@typo3.org>