Implement support for takedown notices (infra, admin tools, workflow)
Takedown notices are coming, and we need full support to dereference certain contents, like it happens on https://github.com/github/dmca.
This involves several subtasks:
- low level support for blacklisting specified contents (not only URLs, also SWHIDs), with support for regexps
- admin interface to add/remove entries from the blacklist
- a journal of these operations (what was added/removed, when and why, from the blacklist)
- a public webpage that maintains the list of accepted takedown notices
Migrated from T3087 (view on Phabricator)