Coroutine as websocket callback function

There is no way in the web socket when you initialize it to send a coroutine instead of a regular function as the on_message callback. any async is unable to run as part of that or required some workaround.

the change should take place here in my opinion:
https://github.com/coinbase/coinbase-advanced-py/blob/master/coinbase/websocket/websocket_base.py#L508

Start in coinbase/websocket/websocket_base.py around line 508 and trace how on_message callbacks are invoked. Confirm how a coroutine callback should be handled, then verify that an async on_message callback can run without a workaround; the issue does not mention a specific test file.

Written by the indexing model from the issue text.