Connect method is too restrictive

[stiiifff]

Current, the Connect method of the WebSocketClient, and by extension of the JsonRpc & Application classes, is too restrictive:

• It assumes a default URI if no node url is passed
• It uses a hard-coded client certificate for the WSS connection
• It takes only 1 argument (node_url) which means we have to introduce breaking changes if we want/need to pass more args