refactor(angular): removes Events service (#19600)

BREAKING CHANGES

The Events Service in @ionic/angular has been removed. 

- Use "Observables" for a similar pub/sub architecture: https://angular.io/guide/observables
- Use "Redux" for advanced state management: https://ngrx.io

angular/src/index.ts

@@ -20,7 +20,6 @@ export * from './directives/proxies';
 export { AngularDelegate } from './providers/angular-delegate';
 export { ActionSheetController } from './providers/action-sheet-controller';
 export { AlertController } from './providers/alert-controller';
-export { Events } from './providers/events';
 export { LoadingController } from './providers/loading-controller';
 export { MenuController } from './providers/menu-controller';
 export { PickerController } from './providers/picker-controller';