[Feature request] ActivityPub/ATProtocol federation support

[Redo11]

ActivityPub and ATProtocol are protocols for federation of users, their interactions and content.
This would allow users from separate instances of Lyntr, or any other software implementing the federation protocol, to interact with each other. Posts shown on one instance will be federated across to other instances, and users from different instances are able to interact with the post, by liking it, replying to it or relyntring it.
This allows for communities to be built, each own self-managed and open to users, regardless of their server.
ActivityPub is used by massive platforms like Mastodon or Peertube and is maintained and recommended by W3C.
ATProtocol, on the other hand, was created for the service BlueSky.

Both protocols are in a mature status and are used by thousands of instances.

Please implement federation.