API: fully include AIs in state chunks

[nofish]

from here:
https://forum.cockos.com/showthread.php?t=205279

[Meo-Ada Mespotine]

+1 Statechunks should contain everything available, including the AIs

[ovnis]

It's very important to resolve the snapshot issue with automation item !

[nofish]

bump

I guess original FR (fully including AIs with points in envelope state chunks) won't happen as they are stored 'globally' (in project chunk) currently, but having API functions for getting/setting the <POOLEDENV> chunks that would be helpful (e.g. for making SWS work with AIs).

(alternatively Get/SetProjectStateChunk would make this FR redundant)