fix(sidebar): nav link target doesn't work through appHtmlAttr

Author: Hagith

projects/coreui/angular/src/lib/sidebar/app-sidebar-nav/app-sidebar-nav-link.component.html

@@ -2,14 +2,16 @@
   <a *ngSwitchCase="'external'"
     [ngClass]="getLinkClass()"
     href="{{item.url}}"
-    [appHtmlAttr]="item.attributes">
+    [appHtmlAttr]="item.attributes"
+    [target]="item.attributes.target ? item.attributes.target : '_self'">
     <i *ngIf="helper.hasIcon(item)" [ngClass]="item | appSidebarNavIcon"></i>
     <ng-container>{{item.name}}</ng-container>
     <span *ngIf="helper.hasBadge(item)" [ngClass]="item | appSidebarNavBadge">{{ item.badge.text }}</span>
   </a>
   <a *ngSwitchDefault
      [ngClass]="getLinkClass()"
      [appHtmlAttr]="item.attributes"
+     [target]="item.attributes.target ? item.attributes.target : '_self'"
      [attr.disabled]="isDisabled()"
      routerLinkActive="active"
      [routerLink]="[item.url]"