send events to the room

[iammuho]

Related issue: #20

---

This PR enables clients to send the events to the related rooms (like typing.started, typing.stopped) and the API server after process the data (like if the room exists, if the user in in the room etc) will forward the event to the connected websocket users except the sender ID.

Sample Request:

POST /api/v1/chat/room/a0b0b227-8162-40d9-a4dd-1968d22061eb/event HTTP/1.1
...
{
    "event_type": "typing.started"
}

Websocket Message:

{
    "connection_id": "2",
    "type": "room.event",
    "message": {
        "event_type": "typing.started",
        "room_id": "a0b0b227-8162-40d9-a4dd-1968d22061eb",
        "user_id": "b2c2bd94-6e15-4b97-8a0e-105af958d2d3"
    },
    "created_at": 1693490966
}

So the client can parse the data, and show the related field. This is the most extensible solution for not just typing events, but can be configured by the client itself.