Membership updater refactoring (#2541)

* Membership updater refactoring

* Pass in membership state

* Use membership check rather than referring to state directly

* Delete irrelevant membership states

* We don't need the leave event after all

* Tweaks

* Put a log entry in that I might stand a chance of finding

* Be less panicky

* Tweak invite handling

* Don't freak if we can't find the event NID

* Use event NID from `types.Event`

* Clean up

* Better invite handling

* Placate the almighty linter

* Blacklist a Sytest which is otherwise fine under Complement for reasons I don't understand

* Fix the sytest after all (thanks @S7evinK for the spot)

federationapi/routing/invite.go

@@ -26,7 +26,6 @@ import (
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
-	"github.com/sirupsen/logrus"
 )
 
 // InviteV2 implements /_matrix/federation/v2/invite/{roomID}/{eventID}
@@ -144,7 +143,6 @@ func processInvite(
 	// Check that the event is signed by the server sending the request.
 	redacted, err := gomatrixserverlib.RedactEventJSON(event.JSON(), event.Version())
 	if err != nil {
-		logrus.WithError(err).Errorf("XXX: invite.go")
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: jsonerror.BadJSON("The event JSON could not be redacted"),