Client-side HTTP basic authentication support

[thehowl]

HTTP basic authentication is a simple authentication mechanism, implemented directly in the protocol. Because it is integrated at a protocol level, web services can be protected by edge web servers like nginx and caddy, without requiring changes in the application itself.

For instance, I could have a simple caddy set up of a gno.land node, password-protecting its RPC, as follows:

rpc.gno.land {
    reverse_proxy gnoland:26657
    basic_auth {
        # Username "bob", password "hiccup"
        bob $2a$14$Zkx19XLiW6VYouLHR5NmfOFU0z2GTNmpkT/5qqR7hx4IjWJPDhjvG
    }
}

However, this is not supported client-side, for instance in gnokey. The URL-spec compliant syntax for providing basic authentication is prefixing the domain with user:password@, as follows:

https://bob:hiccup@rpc.gno.land:443

It would be nice if our clients, like gnokey and gnoclient, supported basic authentication and automatically added the Authorization header in HTTP requests when provided.

[linhpn99]

@thehowl I will create a PR to address this issue and look forward to your guidance to complete this

[thehowl]

Thanks!