- OsuGroupList.get().deleteSongGroup() will delete a song group from the list.
- OsuGroupList.get().deleteSong() will delete an individual song from the list (must be expanded), and will delete the song group if there are no remaining songs in the group.
- If possible, deleted beatmap files are moved to system trash (using JNA); otherwise, they are deleted immediately. This is done through Utils.deleteToTrash().
Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>