chore: replace BaseException with new Error (#2205)

because BaseException removed from A2 public api

public/docs/_examples/ngmodule/ts/app/core/core.module.ts

@@ -3,8 +3,8 @@
 // #docregion
 // #docregion v4
 import {
-  BaseException, ModuleWithProviders,
-  NgModule, Optional, SkipSelf }  from '@angular/core';
+  ModuleWithProviders, NgModule,
+  Optional, SkipSelf }       from '@angular/core';
 
 import { CommonModule }      from '@angular/common';
 
@@ -26,7 +26,7 @@ export class CoreModule {
   // #docregion ctor
   constructor (@Optional() @SkipSelf() parentModule: CoreModule) {
     if (parentModule) {
-      throw new BaseException(
+      throw new Error(
         'CoreModule is already loaded. Import it in the AppModule only');
     }
   }