feat(ivy): add ngcc ivy switch (#25238)

Provides a runtime and compile time switch for ivy including
`ApplicationRef.bootstrapModule`.

This is done by naming the symbols such that `ngcc` (angular
Compatibility compiler) can rename symbols in such a way that running
`ngcc` command will switch the `@angular/core` module from `legacy` to
`ivy` mode.

This is done as follows:

```
const someToken__PRE_NGCC__ = ‘legacy mode’;
const someToken__POST_NGCC__ = ‘ivy mode’;

export someSymbol = someToken__PRE_NGCC__;
```

The `ngcc` will search for any token which ends with `__PRE_NGCC__`
and replace it with `__POST_NGCC__`. This allows the `@angular/core`
package to be rewritten to ivy mode post `ngcc` execution.

PR Close #25238

packages/core/src/sanitization/html_sanitizer.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {isDevMode} from '../application_ref';
+import {isDevMode} from '../is_dev_mode';
 import {InertBodyHelper} from './inert_body';
 import {_sanitizeUrl, sanitizeSrcset} from './url_sanitizer';