Adds support for GMs in shared channels (#31403)

* Adds support for GMs in shared channels

* Fix linter

* Remove creatorID from slack call

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Co-authored-by: Miguel de la Cruz <miguel@ctrlz.es>

server/channels/app/platform/shared_channel_notifier.go

@@ -145,7 +145,7 @@ func handleInvitation(ps *PlatformService, syncService SharedChannelServiceIFace
 		return errors.Wrap(err, fmt.Sprintf("couldn't find remote cluster %s, for creating shared channel invitation for a DM", *participant.RemoteId))
 	}
 
-	return syncService.SendChannelInvite(channel, creator.Id, rc, sharedchannel.WithDirectParticipant(creator), sharedchannel.WithDirectParticipant(participant))
+	return syncService.SendChannelInvite(channel, creator.Id, rc, sharedchannel.WithDirectParticipant(creator, rc.RemoteId), sharedchannel.WithDirectParticipant(participant, rc.RemoteId))
 }
 
 func getUserFromEvent(ps *PlatformService, event *model.WebSocketEvent, key string) (*model.User, error) {