This function returns the query string referenced by the container. The returned string may contain percent escapes.
assert( url_view( "?first=John&last=Doe" ).encoded_params().buffer() == "first=John&last=Doe" );
Constant.
Throws nothing.
query-params = query-param *( "&" query-param )
query-param = key [ "=" value ]
key = *qpchar
value = *( qpchar / "=" )