Support for the ClimateGuard RadSens Geiger-Muller tube

[jake-b]

This PR is to support the ClimateGuard RadSense dosimeter.
A fun and educational sensor for Meshtastic; not for safety critical applications.

This is an I2C device which integrates nicely into the firmware along side other sensors.

This pairs with a pull [request to add a field and enumeration to the protobufs](Support for the ClimateGuard RadSens Geiger-Muller tube #626)

Changes:

• `detect/ScanI2CTwoWire.cpp - adds the ability to find the device on the I2C bus during scan
• modules/Telemetry/Sensor/CGRadSensSensor.* - adds support for reading the sensor
• modules/Telemetry/EnvironmentTelemetry.cpp- updates to handle the new sensor, also updates the display code to not show temperature/humidity unless it is present in the measurement.

Thanks for your consideration of this, my first contribution to Meshtastic

[caveman99]

Thanks for your contribution, for some minor changes see inline comments.

[GUVWAF]

Since this is a rather specific sensor and we're very close to the flash limit on nRF52 devices, I think it would be good to introduce a macro like MESHTASTIC_EXCLUDE_NICHE_SENSORS in order to exclude this and maybe some other sensors for that platform.

[caveman99]

Since this is a rather specific sensor and we're very close to the flash limit on nRF52 devices, I think it would be good to introduce a macro like MESHTASTIC_EXCLUDE_NICHE_SENSORS in order to exclude this and maybe some other sensors for that platform.

Do you care to have it inside of this, or can i merge it and create another PR? i wanted to introduce exclude_ethernet too...

[GUVWAF]

Do you care to have it inside of this, or can i merge it and create another PR? i wanted to introduce exclude_ethernet too...

I'm fine with merging this as is. PR looks good otherwise.