feat(build): record angular version in the dom (#13164)

modules/@angular/forms/index.ts

@@ -11,6 +11,11 @@
  * @description
  * Entry point for all public APIs of the forms package.
  */
+import {Version} from '@angular/core';
+/**
+ * @stable
+ */
+export const VERSION = new Version('0.0.0-PLACEHOLDER');
 export * from './src/forms';
 
 // This file only reexports content of the `src` folder. Keep it that way.