Types are hard to work out when adding event listeners to the CogsConnection

[tomdixon]

You often need to assign a listener so that you can reference it when removing it. This leads to needing to write out the type for the argument of the listener which isn't simple to do currently.

We should look at adding a utility type here, possibly for the whole listener.

Current code for this looks something like:

  useEffect(() => {
    const listener = (
      event: CogsStateChangedEvent<
        Partial<ManifestTypes.StateAsObject<typeof manifest>>
      >
    ) => {
      if (event.state.State) {
        try {
          // TODO: Do something with state
        } catch (e) {
          console.error("Couldn't parse incoming state", e);
        }
      }
    };

    connection.addEventListener("state", listener);

    return () => {
      connection.removeEventListener("state", listener);
    };
  }, [connection]);