S360/voiceover (#2866)

* S360 Expanded-collapsed menus voiceover

* S360 Read only tab titles on tab group navigation

Author: ReneOv-MSFT

desktop/src/@batch-flask/ui/metrics-monitor/metrics-monitor-metric/metrics-monitor-metric.html

@@ -1,6 +1,6 @@
 <ng-template #preview>
     <div class="preview">
-        <div class="graph">
+        <div class="graph" aria-hidden="true">
             <ng-content select=[blMonitorGraphPreview]></ng-content>
         </div>
         <div class="info">

desktop/src/app/components/pool/graphs/heatmap/legend/nodes-heatmap-legend.html

@@ -6,7 +6,7 @@
     </bl-clickable>
     <div *ngIf="item.category">
         <bl-clickable class="legend-item category" (do)="selectState(item.category, item.category)" [attr.aria-selected]="item.category === highlightedState" [class.highlighted]="item.category === highlightedState"
-            (contextmenu)="openContextMenu(item)">
+            (contextmenu)="openContextMenu(item)" [attr.aria-expanded]="item.category === expandedCategory">
             <div [style.backgroundColor]="item.color" class="color"></div>
             <div class="label">{{item.label}} ({{stateCounter.getCountforCategory(item.category)}})</div>
             <div class="category-expansion">