Use Websockets for Sync Substrate

[thewhaleking]

Our disconnection issues (broken pipe) don't happen in async substrate interface. I theorise this is due to the use of websockets (PyPI package) rather than the websocket stdlib package. We know there's no disconnect with the async websockets, but we need to see if the same holds true of the websockets sync (threading) package.

SubstrateInterface accepts a websockets object arg (which we've used in integration tests #2433 ). I want to initiate the websocket at initialisation of the Subtensor object, and pass this to the SubstrateInterface class for init.