Fix MQTT state bouncing on commands, add compressorFrequency, bug fixes

[melyux]

• Fix bouncing MQTT states on command by keeping track locally of the state

• Add resilience when sending multiple commands in rapid succession by ignoring status callbacks until SEND_ROOM_TEMP_INTERVAL_MS after the last command

• Increase default SEND_ROOM_TEMP_INTERVAL_MS to 45 seconds

• Add compressorFrequency to MQTT state

• Fix temperature setting sanity check to be Fahrenheit-friendly

• Remove vestigial JSON document generation incorrectly left behind after dummy packets were centralized

Resolves #94

[adamderuwe]

This will be nice. Hopefully it can get merged soon.

[gysmo38]

Thank you :)