feat: special function to push customisable switches

[3djc]

Thanks @philmoz for colorlcd UI

Fixes #5487

[3djc]

@elecpower , could you do the Companion piece ?
Basically this adds a special func for radio with customisable switches, with 2 params:

• which switch ? SW1 to SWx (num function switch)
• duration; 0 to 25.5s, store exactly like SDLogs (value is in tenth of seconds)

[elecpower]

@elecpower , could you do the Companion piece ?
Basically this adds a special func for radio with customisable switches, with 2 params:

• which switch ? SW1 to SWx (num function switch)
• duration; 0 to 25.5s, store exactly like SDLogs (value is in tenth of seconds)

Yes

[elecpower]

Subject to a blunder on my part, I'm done, so back to you to test.

[pfeerick]

Rebased on main (due to conflicts from #5523). Only changes I made along the way were to add a few more #if defined(FUNCTION_SWITCHES), which then limited yaml storage changes only to radios with CS... passed build and unit tests locally for TPro, TPro S, T15 and TX16S, but otherwise untested at this point. Feel free to push own rebase if you prefer or if something got clobbered along the way...

[3djc]

Seems to work perfectly ! Thanks @elecpower !

Tested from and to T15

[pfeerick]

Firmware (T20) and Companion (linux) LGTM :)