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

Cargo.toml

@@ -98,6 +98,7 @@ members = [
     "packages/playwright-tests/web",
     "packages/playwright-tests/fullstack",
     "packages/playwright-tests/fullstack-mounted",
+    "packages/playwright-tests/fullstack-routing",
     "packages/playwright-tests/suspense-carousel",
     "packages/playwright-tests/nested-suspense",
     "packages/playwright-tests/cli-optimization",