Adding Angular and dependent packages for testing

third_party/pkg/angular/test/io/test_files/templates/main.dart

+library test_files.main;
+
+import 'package:angular/core/module.dart';
+import 'package:angular/tools/template_cache_annotation.dart';
+
+@NgComponent(
+    selector: 'my-component',
+    templateUrl: 'test/io/test_files/templates/main.html'
+)
+@NgTemplateCache()
+class MyComponent {
+}
+
+@NgComponent(
+    selector: 'my-component2',
+    templateUrl: 'test/io/test_files/templates/dont.html'
+)
+@NgTemplateCache(cache: false)
+class MyComponent2 {
+}
+
+
+@NgComponent(
+    selector: 'my-component3',
+    templateUrl: 'test/io/test_files/templates/dont.html'
+)
+@NgTemplateCache(cache: true)
+class MyComponent3 {
+}