LUA: Add a function to retrieve the landed state

[muramura]

I want to get the value of LANDED_STATE to determine the landing status in LUA. I will add a method to retrieve the LANDED_STATE. This ticket is related to #27221 .

RESULT

LUA SCRIPT

[IamPete1]

Full descriptions please.

You can enumerate the return states like this:

ardupilot/libraries/AP_Scripting/docs/docs.lua

Lines 1416 to 1423 in eb8eeba

	-- get throttle motor output
	---@return integer
	---| '0' # Shut down
	---| '1' # Ground idle
	---| '2' # Spooling up
	---| '3' # Throttle unlimited
	---| '4' # Spooling down
	function motors:get_spool_state() end

[olliw42]

this is a bit strange. There is already a landed_state() in GCS_MAVlink which does exactly the same, so it's a good part code duplication. Also, why should only Copter get this lua.

Note that there had been this PR #25459, proposing to move em to the vehicle class, which should also adress this here.

[muramura]

@olliw42 san.
In my LUA script, I do not use GCS or MAVLink communication.
I want to know if the vehicle has landed.
I will change the name to GET_LANDED_STATE.

[olliw42]

you do not need to use either to call it in lua
the function you define newly here is exactly identical to the function I mentioned is already there. Whatever name you give it, it doesn't change that fact :)

[muramura]

I have implemented the process to determine the LAND state in the COPTER.
By doing this, multiple methods are no longer needed.
I have added a description of the return value to the LUA function.

[peterbarker]

We have is_landing, is_taking_off and get_likely_flying already available to scripts - making this one entirely redundant.

Please re-open if you don't think that's the case.