feature: wrap event payloads in ws

Wrap the events' payloads in an object with fields
- event
- data
so that consuming them off the WebSocket is easier and
one can discern the type of the event explicitly instead
of implicitly fromt he payload content.

src/events.ts

@@ -12,7 +12,7 @@ export function startEvents(
 ) {
   const events = eventsFromQuery.split(',')
   events.forEach((event) => {
-    app.on(event, onEvent)
+    app.on(event, (data: any) => onEvent({event, data}))
     spark.onDisconnects.push(() => app.removeListener(event, onEvent))
   })
 }