Custom Background Music

initial 1.18.2 port
- looping sound instances now cache the sound file to disk and utilize STB Vorbis seeking to greatly improve performance and reduce RAM usage. Files may be left in the cache if the game has an abnormal exit (crash or force quit)
- removed selector NBT filters as they can now be applied inside the selector itself
- removed entity subtype filter as it cannot work with the EntityType registry currently
- replaced music tab-autocompletion with "suggestions", similar to command suggestions.
- custom loops are now just normally registered sounds with added loop points in the sounds.json. Any sounds can be used, but only ones with defined loop points will have a custom loop region.
- Boss spawner no longer chunkloads and caches entity id. Instead, bosses will be despawned when the spawner unloads, and will not be loaded from disk.