Is there a cleaner API for getting feedback about a connection attempt?

[MoralCode]

Currently the connect() and disconnect() methods on Ergometer return void and the consumer of this api needs to subscribe to changes in connection state via monitorConnectionState to see if it worked or not.

Goal:
It would be nice to find a way to provide feedback (even a simple binary true/false) when people call these connection methods as an indication of success or failure.

Possible issues
This might need to wait until after #6 since things might change

[MoralCode]

this is resolved in #17. flutter_reactive_ble has the connect function return a stream of status data that can be closed to disconnect. a much cleaner API than what we had before