Ability for a GCS to get RC Link Info from INAV

[b14ckyy]

Current Behavior

Currently a GCS or any external App can only get RSSI values via MSP2_INAV_ANALOG.
It would be useful if GCS Applications like MWPTools could have the opportunity to get a few more data about the RC Link like LQ, SNR or RSSI dB.

Desired Behavior

There is a feature request for MWPTools to show extended RC Link Info aside from RSSI. Currently that is not possible. stronnag/mwptools#184
It would be good to have that option to monitor the RC link on a GCS.

Suggested Solution

A few options that @stronnag suggested:

• A new message (eg) MSP2_INAV_ANALOG2 that just extends MSP2_INAV_ANALOG with new fields and the consumer can decide which to use
• A new message MSP2_INAV_LQ_SNR that just gets LQ/SNR etc.
• Extend the existing MSP2_INAV_ANALOG message with LQ and maybe SNR information to keep it simple for existing applications to not need a Firmware Version depending selection

Additionally we have the new MSP2_COMMON_SET_MSP_RC_LINK_STATS message to write these information into the FC for MSP-RC Links. #10451
Right now by default these messages never respond by design. On the other hand, we could make them respond to output the data that are stored as well?

EDIT: I also just checked with OlliW and mLRS is sending MSP2_COMMON_SET_MSP_RC_LINK_STATS already with no-reply to feed the FC with data and uses the "ilmi" flag. So it should not break anything if we add a reply to that.

Who does this impact? Who is this for?

People using a GCS like MWP for ling range mission to have an eye on their RC link

Additional context