Add archival of bug tracker databases as well as an unofficial bug tracker per-project

There seems to be a significant oversight in the need to collect bug reports. The most important information to preserve with software code is its bug history. There are many reasons SW Heritage should collect bug reports:

Issues in bug databases are not generally part of git (apart from a recent innovation). They are fragile. Bug reports are a burden to create but easy to lose or destroy.
Sometimes bug databases are sabotaged. Sometimes a forge attacks a project and wipes it out, including the bug reports. This happened recently on a Codeberg project. Or a forge could simly shut its doors and go offline spontaneously without notice.
Sometimes bug db's are lost in migrations from one forge to another.
Some forges restrict access to bug trackers. In the case of gitlab.com, the bug reports are more restricted than the software. That is, Tor users are blocked from even reading bug reports.

As a separate matter, I suggest a step further. Not only to archive bug reports but to create a mechanism for people to submit new original reports. This is important because in some situations people are unwilling or unable to use the official bug tracker, so bug reports are consequently being suppressed by bug discoverers. Also because in some situations a developer might suppress a bug report, such as when someone discovers a deliberate tracker in the code that benefits the creator but works against the users.

Migrated from T3235 (view on Phabricator)