[lfs] Prevent aliases from shadowing app names

This is probably somewhat unlikely to actually happen given
that app names are largely random strings and only some are
actual words, but just to be sure we declare app names to be
collisions.

legendary/lfs/lgndry.py

@@ -361,6 +361,8 @@ class LGDLFS:
         alias_map = defaultdict(set)
 
         for app_name in self._game_metadata.keys():
+            # Prevent app names from being used as aliases
+            collisions.add(app_name.lower())
             game = self.get_game_meta(app_name)
             if game.is_dlc:
                 continue