[feature] Federate pinned posts (aka featuredCollection) in and out (#1560)

* start fiddling

* the ol' fiddle + update

* start working on fetching statuses

* poopy doopy doo where r u uwu

* further adventures in featuring statuses

* finishing up

* fmt

* simply status unpin loop

* move empty featured check back to caller function

* remove unnecessary log.WithContext calls

* remove unnecessary IsIRI() checks

* add explanatory comment about status URIs

* change log level to error

* better test names

internal/api/activitypub/users/outboxget.go

@@ -101,7 +101,8 @@ func (m *Module) OutboxGETHandler(c *gin.Context) {
 	}
 
 	if format == string(apiutil.TextHTML) {
-		// redirect to the user's profile
+		// This isn't an ActivityPub request;
+		// redirect to the user's profile.
 		c.Redirect(http.StatusSeeOther, "/@"+requestedUsername)
 		return
 	}
@@ -129,7 +130,7 @@ func (m *Module) OutboxGETHandler(c *gin.Context) {
 		maxID = maxIDString
 	}
 
-	resp, errWithCode := m.processor.Fedi().OutboxGet(apiutil.TransferSignatureContext(c), requestedUsername, page, maxID, minID, c.Request.URL)
+	resp, errWithCode := m.processor.Fedi().OutboxGet(apiutil.TransferSignatureContext(c), requestedUsername, page, maxID, minID)
 	if errWithCode != nil {
 		apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
 		return