Add isObjectMoving to server side

[FileEX]

This PR adds the isObjectMoving function also on the server side, making it available as a shared function.

Test server-side code

local object

addCommandHandler('obj', function(plr,cmd)
	local x,y,z = getElementPosition(plr);
	object = createObject(1337, x,y,z);

	moveObject(object, 20*1000, 0,0,5);
end);

addCommandHandler('objm', function(plr,cmd)
	print(isObjectMoving(object));
end);