filepathfilter: implement String() on *doubleWildcardPattern
filepathfilter: implement String() on *doubleWildcardPattern

dakotahawkins/git-lfs,Jericho25/-git-lfs_miilkyway,aleb/git-lfs,github/git-lfs,dakotahawkins/git-lfs,dakotahawkins/git-lfs,aleb/git-lfs,aleb/git-lfs,github/git-lfs,Jericho25/-git-lfs_miilkyway,github/git-lfs,Jericho25/-git-lfs_miilkyway