ATS MQTT Client

- Add simple charts for each serie, next to current value.
- Add trends for each serie, next to current value.
- Fetch data for series from the server's databases instead of via MQTT (data for devices of all types should be available right away).
- Add automatic data refresh if the data is stale, after bringing app to foreground.
- Change PWM controls for LK (with SW 1.49+)
- Improve visual feedback of using output button.
- Fix some stability issues (addresses blank screen cases).