feat(notification): display app errors, close #319 (#333)

* refactor(log): Refactor logging service

Removed the InjectionToken and changed LogService as default logger.
Finally ElectronLogService implements LogService directly.

* refactor: Optimize imports

* fix(app-update): Add missing rxjs imports

* style: Remove extra line

* refactor(store): Move app.actions.ts to shared module

* feat(notification): Add notification panel

Add angular-notifier to the app and created the ShowNotificationAction
to manage notifications

* style(notification): Fix tslint suggestion

* fix(notification): Add missing rxjs imports

shared/src/services/logger.service.ts

@@ -1,15 +1,7 @@
-import {Injectable, InjectionToken} from '@angular/core';
-
-export interface ILogService {
-
-    error(...args: any[]): void;
-    info(...args: any[]): void;
-}
-
-export let LOG_SERVICE = new InjectionToken('logger-service');
+import {Injectable} from '@angular/core';
 
 @Injectable()
-export class ConsoleLogService implements ILogService {
+export class LogService {
     error(...args: any[]): void {
         console.error(args);
     }