Send email to the author when a content is hidden

Is your feature request related to a problem? Please describe.
Currently, when a content is moderated, the admin can decide to hide the proposal or, if the number of reports exceeds the configuration Decidim.max_reports_before_hiding. This is done by the Decidim::Admin::HideResource command. Which results on hiding the proposals and creating a notification on the user who created the proposal, but it does not send and email.

Describe the solution you'd like
 Send email to the author when a content is hidden

Describe alternatives you've considered

Welcome!

Additional context
Technical specifications: https://github.com/openpoke/decidim/issues/22

Related to Damage (& Idea-) Report

Does this issue could impact on users private data?

No

Funded by

City of Luzern

*We are aware that there is a redesign policy (https://github.com/decidim/decidim/discussions/9512), but we would like to know if this can be accepted once the redesign is done.