Add an error component

Shows when a rendering error has been triggered, like the one in 5edc402a01

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/router/index.ts

@@ -157,5 +157,10 @@ const router = new Router({
 });
 
 router.beforeEach(authGuardIfNeeded);
+router.afterEach(() => {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
+  router.app.$children[0].error = null;
+});
 
 export default router;