chore(tsickle): add @Annotation annotations

This lets users continue using runtime-sideeffect Decorators if they choose,
only down-leveling the marked ones to Annotations.

Also remove the "skipTemplateCodegen" option, which is no longer needed
since Angular compiles with tsc-wrapped rather than ngc. The former doesn't
include any codegen.

modules/@angular/compiler-cli/integrationtest/src/a/multiple_components.ts

@@ -22,7 +22,7 @@ export class HasCustomDecorator {
 
 // Verify that custom decorators have metadata collected, eg Ionic
 export function Page(c: any): (f: Function) => void {
-  return c;
+  return NotADirective;
 }
 
 @Page({template: 'Ionic template'})

modules/@angular/compiler-cli/tsconfig-es5.json

@@ -1,7 +1,4 @@
 {
-  "angularCompilerOptions": {
-    "skipTemplateCodegen": true
-  },
     "compilerOptions": {
         "module": "commonjs",
         "target": "es5",