VST3 support

[CharlesHolbrow]

There's a lot to do here, but much of the hardest work is already done.

• My post requesting access to the component ID
• In VST3 Crashing Due to IEditController Thread Issues, t0m said that they are working on adding support
• My VST Chunk Inspector repo has info about the Reaper's VST3 plugin chunk format
• Schwa's answer on the reaper forums about chunk state

The biggest obstacle right now is getting the full state from JUCE.