Implement federated moderation for ActivityPub

Goal

To allow Minds to become aware of bad content on the Fediverse, and for Minds to notify other sites about content we have reported, we should implement the Flag activity type

What needs to be done

See https://docs.joinmastodon.org/spec/activitypub/#Flag

Example payload (from mastodon)

{
    "@context": "https://www.w3.org/ns/activitystreams",
    "id": "http://mastodon.local/982b445b-9876-4591-94dc-a7a2542de91c",
    "type": "Flag",
    "actor": "http://mastodon.local/actor",
    "content": "",
    "object": [
        "http://d560-129-213-177-45.ngrok-free.app/api/activitypub/users/1521521911551496210"
    ]
}

QA

UX/Design

Mobile

• Is Mobile Required?

Personas

Experiments

Acceptance Criteria

• When a Minds post is reported (and upheld by an admin), we should create a 'Flag' event and propagate out to all domains
• Minds should process Flag activity and generate reports if the entity exists

Definition of Ready Checklist

• Definition Of Done (DoD)
• Acceptance criteria
• Weighted
• QA
• UX/Design
• Personas
• Experiments