feat: update to Angular 8, Nebular 4 (#2114)

src/app/@theme/components/header/header.component.html

@@ -1,26 +1,29 @@
-<div class="header-container"
-     [class.left]="position === 'normal'"
-     [class.right]="position === 'inverse'">
-  <div class="logo-containter">
-    <a (click)="toggleSidebar()" href="#" class="navigation"><i class="nb-menu"></i></a>
-    <div class="logo" (click)="goToHome()">ngx-<span>admin</span></div>
+<div class="header-container">
+  <div class="logo-container">
+    <a (click)="toggleSidebar()" href="#" class="sidebar-toggle">
+      <nb-icon icon="menu-2-outline"></nb-icon>
+    </a>
+    <a class="logo" href="#" (click)="navigateHome()">ngx-<span>admin</span></a>
   </div>
-  <ngx-theme-switcher></ngx-theme-switcher>
+  <nb-select [selected]="currentTheme" (selectedChange)="changeTheme($event)" status="primary">
+    <nb-option *ngFor="let theme of themes" [value]="theme.value"> {{ theme.name }}</nb-option>
+  </nb-select>
 </div>
 
 <div class="header-container">
-  <ngx-layout-direction-switcher></ngx-layout-direction-switcher>
-  <nb-actions
-    size="medium"
-    [class.right]="position === 'normal'"
-    [class.left]="position === 'inverse'">
-    <nb-action *nbIsGranted="['view', 'user']" >
-      <nb-user [nbContextMenu]="userMenu" [name]="user?.name" [picture]="user?.picture"></nb-user>
-    </nb-action>
-    <nb-action class="control-item" disabled icon="nb-notifications"></nb-action>
-    <nb-action class="control-item" icon="nb-email"></nb-action>
+  <nb-actions size="small">
+
     <nb-action class="control-item">
-      <nb-search type="rotate-layout" (click)="startSearch()"></nb-search>
+      <nb-search type="rotate-layout"></nb-search>
+    </nb-action>
+    <nb-action class="control-item" icon="email-outline"></nb-action>
+    <nb-action class="control-item" icon="bell-outline"></nb-action>
+    <nb-action class="user-action" *nbIsGranted="['view', 'user']" >
+      <nb-user [nbContextMenu]="userMenu"
+               [onlyPicture]="userPictureOnly"
+               [name]="user?.name"
+               [picture]="user?.picture">
+      </nb-user>
     </nb-action>
   </nb-actions>
 </div>