feat(platform-server): renderApplication now accepts a bootstrapping method (#49248)

The `renderApplication` now also accepts a bootstrapping function call with return `Promise<ApplicationRef>`as the first parameter.

Example:
```ts
 const bootstrap = () => bootstrapApplication(RootComponent, appConfig);

 const output: string = await renderApplication(bootstrap);
```

PR Close #49248

goldens/public-api/platform-server/index.md

@@ -4,6 +4,7 @@
 
 ```ts
 
+import { ApplicationRef } from '@angular/core';
 import { EnvironmentProviders } from '@angular/core';
 import * as i0 from '@angular/core';
 import * as i1 from '@angular/common/http';
@@ -47,6 +48,13 @@ export class PlatformState {
     static ɵprov: i0.ɵɵInjectableDeclaration<PlatformState>;
 }
 
+// @public
+export function renderApplication<T>(bootstrap: () => Promise<ApplicationRef>, options: {
+    document?: string | Document;
+    url?: string;
+    platformProviders?: Provider[];
+}): Promise<string>;
+
 // @public
 export function renderApplication<T>(rootComponent: Type<T>, options: {
     appId: string;