Add Chirpy support to databank

[johanoskarsson]

I just backed the Sensor Watch Pro campagin, so I figured I'd check out the code a bit. This PR adds Chirp support to the databank to get the data back out of the watch again.

I closely followed the chirpy demo code. More comments inline.

However: one issue remains. Since the light and alarm buttons are already used in both short press and long press I'm not sure what I should be using to trigger the chirping. One idea was simultaneous presses of the light and alarm buttons? I notice there is no specific event for this. I could probably work around that but I figured I'd ask for advice.