Drop MSP_ANALOG frame support

[DzikuVx]

All clients are required to switch to MSP2_INAV_ANALOG frame instead that provides all relevant data

[stronnag]

Appreciate your point about "All clients are required to switch to MSP2_INAV_ANALOG"; but this is exactly how we lost third party tools like 'Ezgui' and 'Mobile Flight'.

If the 3rd party client wants to support other MSP based FCs / older INAV, rather than testing for different versions of "ANALOG", history suggests that they may just not bother.

[sensei-hacker]

I'm curious how many third-party applications exist at this point. I know two third parties, and one of those is rather close to being first party.

If there are only one or two of any consequence, perhaps we could consider those two specifically?

[DzikuVx]

The list of clients is rather short indeed. EzGui was lost for multiple reasons, changing API was one of them.
I do wonder how long we should keep support for frames that have better alternatives

[b14ckyy]

SB app and MWP are the most important still maintained ones and FlyMe2TheMoon LUA is the third one currently implementing INAV support. I assume he will go for up2date stuff anyway. And don't forget impload.