[roq-api] Manage unknown request status

[thraneh]

There are some scenarios which will leave an order request in an unknown state.

Specifically, this was identified with Binance returning HTML when a JSON response was expected.
The request status was not changed for this scenario.

This issue is meant to deal with

• A new enum value will be introduced to manage the unknown request status: RequestStatus::ERROR. This allows us to communicate an OrderAck back to the client so it can take appropriate action.
• The timeout logic should be implemented by the gateways. Although this logic could be implemented by the clients, it feels more natural to centralise the monitoring.

[thraneh]

The underlying issue (Binance) was related to rate-limitation and lock-out and was dealt with as such.

Moving this item to roadmap for now.