Update unit tests websocket

[thewhaleking]

Updates unit tests to use the mocked websocket that is now used for subtensor instantiation.

[basfroman]

I've tested this changes and them are solving the real-chain-call problem partially. We still have 39 unit-tests broken without the connection.

But I believe those tests are old one and doesn't related with websockt update.
Anyway we need to create the issue for to fix this behavior.