Support function: Set different battle music for different bosses

[Rockstar-1998]

Reactive Music is indeed a very good mod, but it has a very fatal problem: it cannot set different battle music for different bosses. If all bosses use the same background music, it will become very boring!

[muon-rw]

Just to expand on this, I think an "ENTITY_TYPE=resource:location" condition that checks for an entity in (maybe configurable) radius would be perfect! An ENTITY_TYPE_TAG or allowing # in ENTITY_TYPE to specify tags would also be very useful.