Handle nil/non-bool returns for keyHandlers

[PabstMirror]

When user added key handler returns bad data, arma throws a generic unhelpful error.

Error in expression <#line 1 "x\cba\addons\events\fnc_keyHand>
 Error position: <#line 1 "x\cba\addons\events\fnc_keyHand>
 Error Type Script, expected Bool

_blockInput is returned at bottom of our function, so if a handler returns bad data, our function will return it as well.

LOG( won't show under normal debug; we could swap to WARNING( if we want to give feedback (this is what we had before #284)?

keyHandlerUp is similar, but doesn't return the results, so it shouldn't matter there.

[Killswitch00]

If a WARNING could show enough info to help indicate which handler (read: which addon/mod component) that's broken, that would be useful.

[commy2]

I think it would be better if we replace L:70
_blockInput
with:
!isNil "_blockInput" && {_blockInput isEqualType true}

Benefits:

• it's closer to all other event handlers that use a boolean true to overwrite something - if you return anything else than a boolean or nil, it is treadted just like false
• no RPT spam for addons that probably won't be updated (ever again or soon)
• you don't have to check this condition multiple times (for every active keybinding) every frame you hold down at least one key.

[PabstMirror]

@Killswitch00 the logging would work like this:

["A", "B", ["C", "D"], { systemChat "x";}, {}, [16, [false, false, false]]] call cba_fnc_addKeybind;
->
...keyHandlerDown.sqf:54","Keybind Handler returned nil or non-bool:  _x=a_b_down,  _blockInput=any"]

a_b should make it easy to id the mod. But I agree with commy2, and I don't think it's worth throwing an rpt for each keypress when an addon returns nil. I left the logging in, but it would only run with DEBUG_MODE_FULL

[Killswitch00]

Yeah, commy2 made good points and I agree with his no-spam suggestion