Get calling GML function as normalized-string

GMFUNCTION_NAME.gml

#macro _GMFUNCTION_NAME_ array_first(string_split_ext(_GMFUNCTION_, ["gml_Script_", "gml_Object_", "gml_GlobalScript_", "@"], true, 2))

/*
function test() {
	show_message(_GMFUNCTION_NAME_); // test
	function does_this() {
		show_message(_GMFUNCTION_NAME_); // does_this
		var a = function even_work() {
			show_message(_GMFUNCTION_NAME_); // even_work
			var b = function() {
				show_message(_GMFUNCTION_NAME_); // anon
			}
			b();
		}
		a();
	}
	does_this();
}
test();
*/