Do return the protocol part from GetLocaltion() for local wxFSFiles.

Do return the protocol part from GetLocaltion() for local wxFSFiles.

wxLocalFSHandler created wxFSFile without the protocol information which means
that calling GetLocaltion() on this file later doesn't return it, contrary to
the documentation.

Do include the protocol to fix this.

Closes #14638.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72649 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775