feat(core): expose inputs, outputs and ngContentSelectors on ComponentFactory. (#15214)

E.g. for a component like this:
```
@Component({
  template: ‘<ng-content select=“child”></ng-content>’
})
class MyComp {
  @Input(‘aInputName’)
  aInputProp: string;

  @Output(‘aEventName’)
  aOuputProp: EventEmitter<any>;
}
```

the `ComponentFactory` will now contain the following:
- `inputs = {aInputProp: ‘aInputName’}`
- `outputs = {aOutputProp: ‘aOutputName’}`
- `ngContentSelectors = [‘child’]`

packages/core/src/linker/compiler.ts

@@ -73,6 +73,8 @@ export class Compiler {
    * the template of the given component.
    * This is used by the `upgrade` library to compile the appropriate transclude content
    * in the AngularJS wrapper component.
+   *
+   * @deprecated since v4. Use ComponentFactory.ngContentSelectors instead.
    */
   getNgContentSelectors(component: Type<any>): string[] { throw _throwError(); }