Settings loader mandatory fixes

- mandatory empty check if empty list ([''])
- skip regex check if replace value is None -> allowed empty as empty if not mandatory

uv.lock

@@ -44,7 +44,7 @@ wheels = [
 
 [[package]]
 name = "corelibs"
-version = "0.12.0"
+version = "0.12.1"
 source = { editable = "." }
 dependencies = [
     { name = "jmespath" },