Add functionality to End Session button in session/[id]/client.tsx

[foleyash]

The end session button within a session needs to be implemented. To end a session, look at the destroySession function inside of socket/WebSocketController.ts, will need to add a broadcast message to all members in the session (io.to(sid).emit("");), and add the subsequent event handler inside of the client side code (session/[id]/client.tsx).

[foleyash]

End session button and exit session button implemented with this commit.