Extend alsoKnownAs, rel=me, etc to all bridged identities

[snarfed]

Right now, when we create/serve bridged identities like AP actors and ATProto DID docs, we publish the original account's identity in rel=me or alsoKnownAs. Background in #1331. A next step here would be to add other bridged identities there too.

For example, blog.anew.social's bridged DID doc currently has:

  "alsoKnownAs": [
    "at://blog.anew.social.web.brid.gy",
    "https://blog.anew.social/"
  ],

blog.anew.social is also bridged into the fediverse as https://web.brid.gy/blog.anew.social, so ideally that AP actor id should also be in the DID doc. And vice versa.