Implement new RoomVersionImpl API (#3062)

As outlined in https://github.com/matrix-org/gomatrixserverlib/pull/368

The main change Dendrite side is that `RoomVersion` no longer has any
methods on it. Instead, you need to bounce via `gmsl.GetRoomVersion`.

It's very interesting to see where exactly Dendrite cares about this.
For some places it's creating events (fine) but others are way more
specific. Those areas will need to migrate to GMSL at some point.

roomserver/internal/query/query.go

@@ -884,12 +884,14 @@ func (r *Queryer) QueryRestrictedJoinAllowed(ctx context.Context, req *api.Query
 	if roomInfo == nil || roomInfo.IsStub() {
 		return nil // fmt.Errorf("room %q doesn't exist or is stub room", req.RoomID)
 	}
+	verImpl, err := gomatrixserverlib.GetRoomVersion(roomInfo.RoomVersion)
+	if err != nil {
+		return err
+	}
 	// If the room version doesn't allow restricted joins then don't
 	// try to process any further.
-	allowRestrictedJoins, err := roomInfo.RoomVersion.MayAllowRestrictedJoinsInEventAuth()
-	if err != nil {
-		return fmt.Errorf("roomInfo.RoomVersion.AllowRestrictedJoinsInEventAuth: %w", err)
-	} else if !allowRestrictedJoins {
+	allowRestrictedJoins := verImpl.MayAllowRestrictedJoinsInEventAuth()
+	if !allowRestrictedJoins {
 		return nil
 	}
 	// Start off by populating the "resident" flag in the response. If we

roomserver/internal/query/query_test.go

@@ -54,7 +54,7 @@ func (db *getEventDB) addFakeEvent(eventID string, authIDs []string) error {
 		return err
 	}
 
-	event, err := gomatrixserverlib.RoomVersionV1.NewEventFromTrustedJSON(
+	event, err := gomatrixserverlib.MustGetRoomVersion(gomatrixserverlib.RoomVersionV1).NewEventFromTrustedJSON(
 		eventJSON, false,
 	)
 	if err != nil {