Fix crash in module 'gtk-menu-actions' on incremental folder.

Incremental folder may not have full file info on itself when it opened.
The gtk-menu-actions module does not check that therefore it crashes on
opening search:// folders. The commit adds check, those folders are not
supported by the module due to that (and that is reasonable).
[#3615191]Return matched directory on search:// itself.

If we enter directory then test it for match then we get incorrect
result which seems as directory lies inside of itself. We should
do check before entering directory and enter if it doesn't match.