feat: export authorization metadata to user extended data

[moustachu]

Usage example :

bundle exec rails authorizations:export_to_user_extended_data AUTHORIZATION_HANDLE_NAME=extended_socio_demographic_authorization_handler

[Quentinchampenois]

Nice solution, I just have little feedbacks

[Quentinchampenois]

We should use another Service or adapt this one because the after_commit hook will fetch all authorizations for a given user and update every time her extended_data column.
In the after_commit hook we should update directly the extended_data column

Example:

Suggested change

	Decidim::AuthorizationDataToUserDataService.run(name: name, user: user)
	extended_data = user.extended_data
	extended_data.merge!({ name.to_s => authorization.metadata })
	user.extended_data = extended_data
	user.save

[moustachu]

The service is already filtered with the name of the authorization (and it's not possible to have 2 authorizations with the same name and user).
The idea was to avoid duplicate the code if we need to edit the part that handle the data update.