feat: add UI for settings and app configuration (#90)

Add settings and app configuration UI for web app and self service
applications.

src/app/core/shell/sidenav/sidenav.component.html

@@ -19,7 +19,7 @@
         Abhay Chawla
       </span>
       <div class="app-user-controls">
-        <button class="text-muted xs-button" mat-icon-button>
+        <button class="text-muted xs-button" mat-icon-button matTooltip="Settings" routerLink="/settings">
           <mat-icon>settings</mat-icon>
         </button>
         <button class="text-muted xs-button" mat-icon-button matTooltip="Sign Out" (click)="logout()">

src/app/core/shell/toolbar/toolbar.component.html

@@ -107,7 +107,7 @@
 <mat-menu #selfServiceMenu="matMenu" [overlapTrigger]="false">
   <span (mouseleave)="selfServiceMenuTrigger.closeMenu()">
     <button mat-menu-item routerLink="/self-service/users">User Management</button>
-    <button mat-menu-item>App Configuration</button>
+    <button mat-menu-item routerLink="/self-service/app-configuration">App Configuration</button>
     <button mat-menu-item>Task Management</button>
   </span>
 </mat-menu>