Add Activity View API

This will be the api that drives the activities views. The idea here is to make a scalable and straightforward way to build activities with friends making video chat a first class citizen.

```
ActivityState: { // Available Globally
peers: Peer[]; // All active peers
activePeerIds: string[]; // All active peer ids
selectedPeerId: string; // The currently selected peer id
timer: null | number; // null if not set
}

Events:
onPeerAdded(peer)
onPeerRemoved(peer)
onPeerSelected(prevSelectedPeer, nextSelectedPeer)
onTimerStarted(activityState)
onTimerFinished(activityState)
onActivityStart(activityState)
onNext(activityState)

Actions:
getActivePeersLength();
getRandomNumber(min, max);
selectPeer(peer.id)
selectNextPeer()
selectPreviousPeer()
selectRandomPeer()
movePeerToPosition(peerId, position)
setPeerText(peerId, text);
setCenterText(text);
setTimer(time);
setActivePeers(peerIds)
forEachActivePeer();
requestText();

// Guess Who Game
{
onActivityStart(() => {
forEachActivePeer((peer) => {
requestText(() => setPeerText(peer.id));
})
selectRandomPeer();
}),
onPeerSelected((prev, next) => {
movePeerToPosition('center');
setCenterText(next.peerText);
}),
onNext(() => {
selectNextPeer();
})
}
```