Add shared inbox support for ActivityPub delivery (#4755)

* feat(ap): add support for shared inboxes to reduce outbound load

* feat(db): refactor ap followers db into followers repository

* fix(ap): use the updated activity library to pull out the shared inbox endpoint

* chore(deps): point at updated build of owncast/activity

* fix(ap): typeless endpoints

* feat(test): update ActivityPub test to support shared inboxes

* chore(test): remove unused variable

* fix: feedback from review. Guard against SSRF/non-HTTPS/local and handle transaction errors

activitypub/inbox/worker.go

@@ -13,7 +13,7 @@ import (
 
 	"github.com/go-fed/httpsig"
 	"github.com/owncast/owncast/activitypub/apmodels"
-	"github.com/owncast/owncast/activitypub/persistence"
+	"github.com/owncast/owncast/activitypub/persistence/followersrepository"
 	"github.com/owncast/owncast/activitypub/resolvers"
 	"github.com/owncast/owncast/persistence/configrepository"
 
@@ -148,7 +148,8 @@ func isBlockedDomain(domain string) bool {
 }
 
 func isBlockedActor(actorIRI *url.URL) (bool, error) {
-	blockedactor, err := persistence.GetFollower(actorIRI.String())
+	followersRepo := followersrepository.Get()
+	blockedactor, err := followersRepo.GetByIRI(actorIRI.String())
 
 	if blockedactor != nil && blockedactor.DisabledAt != nil {
 		return true, errors.Wrap(err, "remote actor is blocked")