ADSB RX App cleanup

[kallanreed]

Part half of attempt to understand why this app likes to stop working. The intention here was to do some thorough code gardening to see if there was something obvious that could be fixed. Also, I wanted to add some status indicators so if the problem happens again, we might have a better understanding about where the problem is.

Summary of changes:

• I'm happy with the rewrite - was able to remove a lot of dead code and simplify quite a few ideas.
• I didn't find any "smoking gun" which would indicate a problem in this layer so that points to a problem in the proc.
• Added two status "dots" -- on that shows whenever a frame is passed up from Baseband, and a second whenever that frame passes CRC and has a valid ICAO key.

There is some slight differences in behavior w.r.t. how processing happens when there are more than 16 entries. I wasn't sure what the original code was attempting to solve for, but what I did was split apart list maintenance and UI redraw in that case so it's not doing a ton of work every tick when the list gets large. It might make more sense to chunk the work if there's more than 16, but you can't really chunk a sort/expiration.

One thing I did notice was that occasionally (usually immediately after flashing) I was seeing lots of frames come through without any of them being accepted. That lends more evidence to the idea that the proc is broken somehow.
Perhaps it's getting out of phase or something? It's just odd that it sends so much data that is just rejected.

[gullradriel]

Good to go. Nice cleaning, it's already more clear to read.
Thanks Kal 👍

[gullradriel]

@kallanreed I'm leaving the closing of the conversations to you, be assured that I read all your comments :-)