Optimistically report changes to esphome

[pgenera]

this makes two changes:

• when receiving a new setpoint or mode from esphome, immediately report it back as the current status without waiting for it to round-trip through the heat pump. This means that temperatures set in F will wait 30 seconds before being converted to C, which feels weird but is, at least, very easy.

• When in HEAT, COOL or DRY, report the current hvac 'action' very simplistically: if the current tempertaure is above/below the set point, then you're doing the current action. This doesn't reflect what the heat pump is actually doing, but it is prettier.

[jamescadd]

Just tested this briefly and it works well for me - much better experience in the UI for both the normal HA thermostat and simple thermostat. I'll continue using it and note any issues, but for now I think it would be a welcome improvement - thanks for this!

[geoffdavis]

Thanks, let me give it a shot on my system here.

[geoffdavis]

This looks great. I like the responsiveness of the UI, even if it still acts a little jumpy doing the conversions from F to C to F again. I had hesitated to implement the optimistic state changes, but it looks like it corrects itself just fine if the command doesn't take effect for whatever reason.