Pass adress and port independently to constructor.

[clangenb]

Change the Api::new(url: String) to Api::new(address: &str, port: &str). Practice shows that this is more convenient as all our CLI`s fetch the url and the port independently, which leads to boilerplate code outside the Api.

Note: &str suffices, as we will assemble the String internally with format!

[haerdib]

@clangenb api-client now offers the function new_with_port for all rpc clients. Only took 3 years 🥳