Site events

[SteveEdson]

In V5, when editing, adding or deleting a site, it would be good to fire an event, like Statamic does for other content types.

This way, we can hook into it to:

• clean up the content files which are left over when the site is deleted
• move the content files if the handle changes
• create some skeleton files for new sites

[Sennik]

I agree to this and I like to add a feature related to this:

When creating a new site it would be nice to have the option to start with a copy of the content of an existing site. My translators prefer translating content by replacing it with their language and I personally like to start with structure/content when I am adding a new site to a multisite configuration.

[jackmcdade]

Closing this FR because we're already working on it here! statamic/cms#10403