routes::get_handler should treat a path parameter as a route definition

[ewienik]

If a parameter is defined for an url it should be treat as part of an url in matching rules process. This test should pass:

SEASTAR_TEST_CASE(test_match_rule_order_with_param) {
    parameters param;
    routes route;

    handl* h1 = new handl();
    route.add(operation_type::GET, url("/hello").remainder("path"), h1);

    handl* h2 = new handl();
    route.add(operation_type::GET, url("/hello"), h2);
    
    auto rh = route.get_handler(GET, "/hello/path-arg", param);
    BOOST_REQUIRE_EQUAL(rh, h1);

    rh = route.get_handler(GET, "/hello", param);
    BOOST_REQUIRE_EQUAL(rh, h2);                           // <-- currently failed

    return make_ready_future<>();
}