report signal strength in dBm over MQTT

[RoadRunnr]

Description:

• report signal strength in dBm over MQTT
• include dBm in debug log and in WebIf information display.

Related issue (if applicable): fixes #7113

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on core 2.6.1
• The code change pass travis tests. Your PR cannot be merged unless tests pass
• I accept the CLA.

[arendst]

Great!

As for me just get rid of the setoption. Makes code smaller and dBm is implemented nicely.

So pls remove setoption and I'll merge

[ascillato]

So as to not break backwards compatibility, the JSON message will include both values? RSSI % and dBm?

[arendst]

It's just an additional json field/value pair so should be no issue for json processors.

[arendst]

Ah I see. I choose the wrong name for rssi quality...

[arendst]

But with this solution you have no idea if it's rssi quality or just rssi.

We need a new value pair for rssi in dBm

[ascillato]

We need a new value pair for rssi in dBm

Totally agree.

[RoadRunnr]

updated, SetOption removed, the signal strength is now reported in dBm in a new JSON node called "Signal".

About the JSON, I opted for keeping it as short as possible, it would also be sensible to call it "SignalStrength". Not sure which one is better.