Return a 404 when paring the route fails (#3860)

* return a 404 when paring the route fails

* add a playwright test for fullstack routing status codes

* Fix new playwright test

* document SSRError

* Make SSRError public and fix clippy

* Move the error display bound to the routable trait

* fix clippy

* return a more generic 404 message

* fix router tests

packages/router/src/router_cfg.rs

@@ -43,7 +43,6 @@ impl<R> Default for RouterConfig<R> {
 impl<R> RouterConfig<R>
 where
     R: Routable,
-    <R as std::str::FromStr>::Err: std::fmt::Display,
 {
     /// A function to be called whenever the routing is updated.
     ///