Initial implementation of MSP RC stats and info messages

[MrD-RC]

This work is to kick off the changes asked for in #10363

Requires configurator iNavFlight/inav-configurator#2230

We are adding two new common MSP V2 messages:

• MSP2_COMMON_SET_MSP_RC_LINK_STATS 0x100D
• MSP2_COMMON_SET_MSP_RC_INFO 0x100E

They are called to update the firmware of changes on the MSP RC receiver/transceiver. MSP2_COMMON_SET_MSP_RC_LINK_STATS is sent with every packet and MSP2_COMMON_SET_MSP_RC_INFO is sent periodically and when changes are made. Payload size checking has been set so that the payload must at least meet the current defined payload. Future updates to payload would need to be accounted for in updated versions of INAV. But at least, this base data will still be able to be processed.

MSP2_COMMON_SET_MSP_RC_LINK_STATS

Parameter	Size (Bytes)	Datatype	Min	Max	Units	Notes
Sublink ID	1	uint8	0	7		Used to distinguish particular antennae or transceiver chips on the module
Valid Link	1	uint8	0	1		Used to show if the module has a valid link or is in failsafe
RSSI %	1	uint8	0	100		The RSSI as a 0-100%
Uplink RSSI dB	1	uint8	0	127	dBm	The RSSI in dBm. The value is inverted, so always reads negative or 0. Set to 127 if not used.
Downlink LQ	1	uint8	0	100		LQ for the downlink
Uplink LQ	1	uint8	0	100		LQ for the uplink
Uplink SNR	1	int8	-128	127	dB	SNR for the uplink

MSP2_COMMON_SET_MSP_RC_INFO

Parameter	Size (Bytes)	Datatype	Min	Max	Units	Notes
Sublink ID	1	uint8	0	7		Used to distinguish particular antennae or transceiver chips on the module
Uplink TX Power	2	uint16	0		mW	Uplink power in mW
Downlink TX Power	2	uint16	0		mW	Downlink power in mW
Band	4	char[]				Band - For example: 868M, 915M, 2.4G, DUAL
Mode	6	char[]				Mode - For example: 19Hz, 31Hz, 50Hz. FSK, FLRC, 150Hz, F333Hz, 1000Hz

Changes

• Added MSP commands to store the data from the transceiver
• Added missing OSD elements
• Opened up OSD elements that were previously only used by CRSF
• Added downlink LQ and uplink RSSI to the programming framework

Limitations of current implementation

Due to time constraints. This initial implementation is not a full implementation.

• Currently, only sublink ID 0 will store any data. This will need expanding to allow for up to 8 sublinks.
• Failsafe in the link stats is not used. There is already a failsafe defined in MSP OVERRIDE. We should look at the options and decide the best route to take with this.
• There are no current OSD elements (I will try to add these before the 15th of November deadline) for:
  • Downlink LQ
  • Downlink TX Power
  • Band
  • Mode
• RSSI %, Uplink RSSI, Uplink LQ, Uplink SNR, and Uplink TX Power work with already existing OSD elements. Some are only active when CRSF is selected. So a change will need to be made to open these up for other systems.

[b14ckyy]

Happy on my end. All elements work. Logic triggers also tested and work as intended. Digital fonts will need an Update but if not updated, just 2 icons missing. String text for Mode and Band is clear and up to the RC Link Developer.