[#3F5D4D3F83FB60E71134ADE4662B002E952A0844]
Return the complete authority
                            
        
            core::string_view
buffer() const noexcept;
        
    This function returns the authority as a percent-encoded string.
assert( parse_authority( "www.example.com" ).value().buffer() == "www.example.com" );
authority   = [ userinfo "@" ] host [ ":" port ]
Throws nothing.