Show chrome in redirect apps to improve navigation between apps (#210586)

## Summary


possibly fixes https://github.com/elastic/kibana/issues/210058

- make it `chromless:false, visibleIn: []` so that in-app redirects via
/r/ route feel smoother as chrome will stay visible
- `<EuiPageTemplate minHeight={0} offset={0}>` places loading/error in
the middle of the screen, remove scroll
- `abortController.signal` to cancel redirect in-case user has already
navigated away while waiting for shortUrl resolve (edge case)
- EuiDelayRender around "Redirecting..." spinner 
- Also do it for `forwardApp` 

### Demo (download and slowdown to see the difference): 


**before in between apps navigation** (chrome remounts for a moment,
adds junk)


https://github.com/user-attachments/assets/36d98ce9-8051-4f91-8dd9-7b406d613a73


**after in between apps navigation** (chome stays, feels smoother)


https://github.com/user-attachments/assets/4ad46954-aefe-4bde-ac4c-d598aac8b8fe


**before initial load** (chrome mounts only with discover)


https://github.com/user-attachments/assets/2618f25d-85fe-4474-8800-cbcb06db4b8e

**after initial load** (chrome mounts earlier, feels like apps loads
faster)


https://github.com/user-attachments/assets/1adc0af3-6c3c-4334-9157-fba2f008d8d5









- As a bonus, because chrome is rendered now, the error state is
friendlier, as it allows to navigate away:

![Screenshot 2025-02-11 at 15 24
29](https://github.com/user-attachments/assets/98fab62a-0ae0-4cc4-8464-c5123470ea81)
![Screenshot 2025-02-11 at 15 24
51](https://github.com/user-attachments/assets/02c455ff-9251-48f5-975c-3586c1fcbc0e)

---------

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

src/platform/plugins/private/url_forwarding/public/forward_app/forward_app.ts

@@ -16,7 +16,6 @@ export const createLegacyUrlForwardApp = (
   forwards: ForwardDefinition[]
 ): App => ({
   id: 'kibana',
-  chromeless: true,
   title: 'Legacy URL migration',
   appRoute: '/app/kibana#/',
   visibleIn: [],

src/platform/plugins/shared/share/public/url_service/redirect/components/page.tsx

@@ -10,7 +10,7 @@
 import * as React from 'react';
 import useObservable from 'react-use/lib/useObservable';
 
-import { EuiPageTemplate } from '@elastic/eui';
+import { EuiPageTemplate, EuiDelayRender } from '@elastic/eui';
 import type { CustomBrandingSetup } from '@kbn/core-custom-branding-browser';
 import type { ChromeDocTitle, ThemeServiceSetup } from '@kbn/core/public';
 import { KibanaThemeProvider } from '@kbn/react-kibana-context-theme';
@@ -42,7 +42,7 @@ export const Page: React.FC<PageProps> = ({
   if (error) {
     return (
       <KibanaThemeProvider {...startServices}>
-        <EuiPageTemplate>
+        <EuiPageTemplate minHeight={0} offset={0}>
           <RedirectEmptyPrompt docTitle={docTitle} error={error} homeHref={homeHref} />
         </EuiPageTemplate>
       </KibanaThemeProvider>
@@ -51,9 +51,11 @@ export const Page: React.FC<PageProps> = ({
 
   return (
     <KibanaThemeProvider {...startServices}>
-      <EuiPageTemplate>
-        <Spinner showPlainSpinner={Boolean(hasCustomBranding)} />
-      </EuiPageTemplate>
+      <EuiDelayRender>
+        <EuiPageTemplate minHeight={0} offset={0}>
+          <Spinner showPlainSpinner={Boolean(hasCustomBranding)} />
+        </EuiPageTemplate>
+      </EuiDelayRender>
     </KibanaThemeProvider>
   );
 };

src/platform/plugins/shared/share/public/url_service/redirect/redirect_manager.ts

@@ -35,8 +35,11 @@ export class RedirectManager {
     application.register({
       id: 'r',
       title: 'Redirect endpoint',
-      chromeless: true,
+      visibleIn: [],
       mount: async (params) => {
+        const abortController = new AbortController();
+        this.onMount(params.history.location, abortController.signal);
+
         const { render } = await import('./render');
         const [start] = await core.getStartServices();
         const { chrome, uiSettings, userProfile } = start;
@@ -50,9 +53,8 @@ export class RedirectManager {
           homeHref: getHomeHref(http, uiSettings),
         });
 
-        this.onMount(params.history.location);
-
         return () => {
+          abortController.abort();
           unmount();
         };
       },
@@ -92,11 +94,11 @@ export class RedirectManager {
     });
   }
 
-  public onMount(location: Location) {
+  public onMount(location: Location, abortSignal?: AbortSignal) {
     const pathname = location.pathname;
     const isShortUrlRedirectBySlug = pathname.startsWith('/s/');
     if (isShortUrlRedirectBySlug) {
-      this.navigateToShortUrlBySlug(pathname.substring('/s/'.length));
+      this.navigateToShortUrlBySlug(pathname.substring('/s/'.length), abortSignal);
       return;
     }
     const urlLocationSearch = location.search;
@@ -104,17 +106,23 @@ export class RedirectManager {
     this.navigate(options);
   }
 
-  private navigateToShortUrlBySlug(slug: string) {
+  private navigateToShortUrlBySlug(slug: string, abortSignal?: AbortSignal) {
     (async () => {
       const urlService = this.deps.url;
       const shortUrls = urlService.shortUrls.get(null);
       const shortUrl = await shortUrls.resolve(slug);
+
+      if (abortSignal?.aborted)
+        return; /* it means that the user navigated away before the short url resolved */
+
       const locatorId = shortUrl.data.locator.id;
       const locator = urlService.locators.get(locatorId);
       if (!locator) throw new Error(`Locator "${locatorId}" not found.`);
       const locatorState = shortUrl.data.locator.state;
       await locator.navigate(locatorState, { replace: true });
     })().catch((error) => {
+      if (abortSignal?.aborted) return;
+
       this.error$.next(error);
       // eslint-disable-next-line no-console
       console.error(error);