Add admin controls for song data changes

[piercy]

With the addition of OST and Mappers not on BeatSaver to the code, we need a way to easily update existing songs data information (like the CoverArt).

Features:

• Should be searchable by many fields (name, author, level author, ost)
• Should be mass updateable - ie, should be able to update all the songs for a selected query easily
• Potentially allow image upload to make it easier to add to these