chore: add GUT test framework

addons/gut/templates/.gutconfig.json

@@ -0,0 +1,9 @@
+{
+  "dirs":["res://test/unit/", "res://test/integration/"],
+  "should_maximize":false,
+  "should_exit":true,
+  "ignore_pause":true,
+  "log": 2,
+  "opacity":100,
+  "include_subdirs":false
+}