New consent model.

Preserves existing UI buttons and behavior. Replacing with a UI that directly
exposes the relevant fields will come later.
Remove FSM code.
Minor cleanup.
Fix field names.

The local*_ fields should be marked private, but having trouble with
ui.spec.ts.
Don't call core.stop from Consent.WireState handling code.

I don't believe it was (usually) called anyway, because access.asProxy is set
to false when the socksToRtc_ connection is broken.
Fix Consent.State usage in UI test, make local*_ fields private.
Remove test. Remote revoking consent no longer stops proxy.