message_definitions: update+add LED_CONTROL_* messages

[Gussy]

• Removes the old (and totally un-used) LED_CONTROL message
• Adds new LED_CONTROL_PATTERN, LED_CONTROL_PATTERN_PARAM, and LED_CONTROL_MACRO messages for full low-level LED control.

[mrpollo]

this should totally be merged ! 👯

[Gussy]

Who want's to do the honors. @liamstask?

[liamstask]

@Gussy: is this intended to be generalizable beyond oreoled? @mrpollo: do you have other plans for it, or just want better oreoled support?

@mrpollo, @jschall: is there any effort to sync w/upstream mavlink? if so, wondering if this should sync with that effort

[jschall]

Please work on top of upstream ardupilotmega.xml from the ardupilot repository if possible.

[jschall]

Can these be implemented as COMMAND_LONGs?

[Gussy]

@liamstask The idea is for them to be generic, yes.

@jschall:
I think rebasing this repo on upstream is for a different PR.
The largest payload is 15 bytes, so these could be COMMAND_LONGs, should I re-write this and the ardupilot-solo patch?

[jschall]

We should probably merge upstream ardupilotmega.xml into this repository, preferably before merging this PR

[jschall]

Can you implement all of this on upstream?

I've rebased these changes on the new ardupilotmega.xml file: https://github.com/jschall/ardupilot/tree/pr-led-control

[jschall]

Went ahead and rebased this PR.