Only show carats for items with children (#410)

* Only show carats for folders with children

* Only show carats for collections with children

src/app/vault/groupings.component.html

@@ -67,7 +67,7 @@
                         <li *ngFor="let f of folders"
                             [ngClass]="{active: selectedFolder && f.node.id === selectedFolderId}">
                             <div class="d-flex">
-                                <i class="fa-li fa" title="{{'toggleCollapse' | i18n}}"
+                                <i *ngIf="f.children.length" class="fa-li fa" title="{{'toggleCollapse' | i18n}}"
                                     [ngClass]="{'fa-caret-right': isCollapsed(f.node), 'fa-caret-down': !isCollapsed(f.node)}"
                                     (click)="collapse(f.node)"></i>
                                 <a href="#" appStopClick (click)="selectFolder(f.node)">{{f.node.name}}</a>
@@ -92,7 +92,7 @@
                 <ul class="fa-ul card-ul carets">
                     <ng-template #recursiveCollections let-collections>
                         <li *ngFor="let c of collections" [ngClass]="{active: c.node.id === selectedCollectionId}">
-                            <i class="fa-li fa" title="{{'toggleCollapse' | i18n}}"
+                            <i *ngIf="c.children.length" class="fa-li fa" title="{{'toggleCollapse' | i18n}}"
                                 [ngClass]="{'fa-caret-right': isCollapsed(c.node), 'fa-caret-down': !isCollapsed(c.node)}"
                                 (click)="collapse(c.node)"></i>
                             <a href="#" appStopClick (click)="selectCollection(c.node)">{{c.node.name}}</a>