The implementation will provide a new entry in the macro tree's context menu: "Save As".
There is a tiny, but somewhat ugly effect: when a macro is Ruby, but it's saved to a Python folder, it won't change the interpreter. The folders are just categories, not imperative. Hence the "save as" feature needs to be used with a little care. Ideally, it's only use to save into the source folder to create a copy of a macro with a different name.