Parse followers audience from followers URI (#7112)

* add followersUri

* add followersUri to audience parse

* fetch followersUri

* followersUri db migration

* update followersUri

* Rename 1611354329133-followersUri to 1611354329133-followersUri.ts

* typo

* Update person.ts

* create/update person consistency

* Update audience.ts

* missing paren

* tabs

* use strict equality

* Update audience.ts

src/remote/activitypub/audience.ts

@@ -86,8 +86,7 @@ function isPublic(id: string) {
 }
 
 function isFollowers(id: string, actor: IRemoteUser) {
-	return [
-		`${actor.uri}/followers`,
-		// actor.followerUri,	// TODO
-	].includes(id);
+	return (
+		id === (actor.followersUri || `${actor.uri}/followers`)
+	);
 }