Add an option not to update caret indicator while caret is still moving

[eugenesvk]

Due to polling delay, the caret indicator is "continuously jumpy", but since you can't type while moving the caret, this is just visual noise

CaretDelayNo.mp4

I think a configurable option could be to not update the indicator until the caret has stopped moving

CaretDelayYes.mp4

Maybe a rudimentary "is any cursor key down" check could work?

  is_cursor_key_down  	:= (GetKeyState("Left"))
    ||                	   (GetKeyState("Right"))
    ||                	   (GetKeyState("Up"))
    ||                	   (GetKeyState("Down"))

(maybe add pagedown/up? Though in the general case you can't detect all cursor moving keys and will also fail on non-key cursor movements)

Or maybe a better option would be to record time since last caret position change and allow user to set the threshold of what counts as "caret stopped moving"

[yakunins]

Prob it is better to update caret pos on every keypress, so it will stick closely...