Receiver causes memory leaks

[Bielik20]

Actions listening never ends:

post-quecast/src/receiver.ts

Lines 56 to 72 in f8a7e9b

	private listenEvent(): void {
	const callback = (event: PostQuecastEvent) => {
	if (!isEventOfChannel(event, this.channelId)) {
	return;
	}
	if (!isEventPublic(event)) {
	return;
	}
	const action = getEventAction(event);
	this.handleActions(action);
	};
	this.connector.addListener(callback);
	}

It would be good to stop listening if there are no callbacks passed to Receiver