Hook into subscription error events

[harrietwaters]

Is your feature request related to a problem? Please describe.
Errors that bubble up from subscriptions (TCP auth, DNS, whatever) are not handled by the library or exposed to the client.

Describe the solution you'd like
A generic handler should be attached to the error event on all subscriptions that catches and re-throws the error. This should somehow also be exposed to the client (error handling strategy doesn't feel right but I'm open to convincing).

Describe alternatives you've considered
Instead of re-throwing we could also just close and re-open the subscription.