Return true if a password is present
This function returns true if the userinfo is present and contains a password.
assert( url_view( "http://jane%2Ddoe:pass@example.com" ).has_password() );
userinfo = user [ ":" [ password ] ]
user = *( unreserved / pct-encoded / sub-delims )
password = *( unreserved / pct-encoded / sub-delims / ":" )
has_userinfo , encoded_password , encoded_user , encoded_userinfo , password , user , userinfo .