Run Meta-System with current configuration and collect its Addons diff

[zelcion]

Description

In order to check the diff between the initial user configuration and the final one, after all the Addons modifications, we need to have a command that returns this information.

The feature already exists, so this issue outlines just a way to expose this information.

This issue will help on the Meta-editor, to have a view showing what each addon changes in the system, and how.

Requirements

We just need a standard way to access this information. Suggestions are welcome.