Flow monitoring: add a real-time flow reading in accessory settings and active watering view

[KevBo]

I had to build my own graphing between Flume and Rachio. Not realtime, but useful for me.

Rachio with Flume

Finally gave up on my Rachio flow meter. Only OK while it lasted. Finally dug in and wrote some code to pull data from Flume and Rachio API to chart house usage vs. Zone. Result below: [Sprinkler Zones vs Flume] ps: Yes - I have some zones that are permanently off. My main goal was to look for leaks and popped heads. Update: one other representation. [Flume vs Zones]