Dynamic Routing Beta: StaticPageRouter pre-checks for redirects

refs #9601

- you can define a redirect in your routes.yaml

e.g. from `page.home` to /about/

- we have to check for a possible redirect before rendering the target static page

core/server/services/routing/StaticPagesRouter.js

@@ -25,6 +25,8 @@ class StaticPagesRouter extends ParentRouter {
     _registerRoutes() {
         this.router().use(this._prepareContext.bind(this));
 
+        this.router().param('slug', this._respectDominantRouter.bind(this));
+
         // REGISTER: permalink for static pages
         this.mountRoute(this.permalinks.getValue(), controllers.entry);