Put entire core processing into a thread

[TonyGiorgio]

I thought this would be a good idea to seperate the subscription thread stuff from core processing, but when I removed the thread spawn around the db unlock part, it did not actually fix the issue we had previously ran into. I think that's just because the thread it's in is still being bottlenecked, but it makes me question whether the whole subscription part is already in a thread anyways and I'm spinning up a new thread here unnecessarily.

I think making mpsc channel 50 is better anyways so I'll break that out into a new commit.

Was just thinking about threading earlier today and whether this would help, figured I'd get a second opinion and we can close it if it's pointless.

Thoughts?

[benthecarman]

this is a good idea, just one small problem