This will allow the user to select two existing profiles, highlight the differences, and create or update a third profile if desired.
To package your plug-in, use the packaging script in Uranium: https://github.com/Ultimaker/Uranium/blob/master/create_plugin.py
Try the following command:
python3 /path/to/Uranium/create_plugin.py /path/to/UraniumExampleExtensionPlugin
That should produce a .plugin file that can be added to any application based on Uranium.