Accept `host:port` for client instead of only URL

[cretz]

Is your feature request related to a problem? Please describe.

All other SDKs use host:port, we should too

Describe the solution you'd like

• Change tls_config: Optional[TLSConfig] = None to tls_config: Union[bool, TLSConfig] = False
• If a scheme is not present (meaning we're backwards compatible here), before sending to core, set it as http if tls_config is false or https otherwise

[cretz]

Maybe I should rename tls_config to tls? I think I will... (that's backwards incompat but who cares)