[#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.