Added native Bazel build to GUI2. Reduced a lot of the unused Angular CLI structures

Reviewers should look at the changes in WORKSPACE, BUILD, BUILD.bazel, README.md files
This is only possible now as rules_nodejs went to 1.0.0 on December 20
gui2 has now been made the entry point (rather than gui2-fw-lib)
No tests or linting are functional yet for Typescript
Each NgModule now has its own BUILD.bazel file with ng_module
gui2-fw-lib is all one module and has been refactored to simplify the directory structure
gui2-topo-lib is also all one module - its directory structure has had 3 layers removed
The big bash script in web/gui2/BUILD has been removed - all is done through ng_module rules
in web/gui2/src/main/webapp/BUILD.bazel and web/gui2/src/main/webapp/app/BUILD.bazel

Change-Id: Ifcfcc23a87be39fe6d6c8324046cc8ebadb90551
diff --git a/web/gui2/src/main/webapp/onos.ts b/web/gui2/src/main/webapp/onos.ts
index cf76512..a9465b6 100644
--- a/web/gui2/src/main/webapp/onos.ts
+++ b/web/gui2/src/main/webapp/onos.ts
@@ -1,12 +1,29 @@
-import { enableProdMode } from '@angular/core';
-import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
+/*
+ * Copyright 2020-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 
-import { OnosModule } from './app/onos.module';
-import { environment } from './environments/environment';
+/**
+ * This main entry point is used to launch the app under the
+ * @angular-devkit/build-angular, which is the default CLI
+ * builder. Note that for AOT, the CLI will magically replace
+ * the bootstrap by switching platform-browser-dynamic with
+ * platform-browser.
+ * This file is completely unused in the Bazel build.
+ */
+import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
 
-if (environment.production) {
-  enableProdMode();
-}
+import {OnosModule} from './app/onos.module';
 
-platformBrowserDynamic().bootstrapModule(OnosModule)
-  .catch(err => console.log(err));
+platformBrowserDynamic().bootstrapModule(OnosModule).catch(err => console.log(err));