chore(*): Change role from compose to rowgroup

This is for the thead wrapper element

Author: zdrawku

package-lock.json

@@ -28,7 +28,7 @@
 </div>
 
 <div class="igx-grid__thead">
-    <div class="igx-grid__thead-wrapper" [class.igx-grid__tr--mrl]='hasColumnLayouts' role="composite" (focus)="navigation.focusFirstCell()"
+    <div class="igx-grid__thead-wrapper" [class.igx-grid__tr--mrl]='hasColumnLayouts' role="rowgroup" (focus)="navigation.focusFirstCell()"
     [style.width.px]='calcWidth' tabindex="0" [attr.aria-activedescendant]="activeDescendant" (keydown)="navigation.headerNavigation($event)" (scroll)="preventHeaderScroll($event)" #theadRow>
         <div class="igx-grid__tr" role="row" [style.width.px]='calcWidth'>
             <span *ngIf="hasMovableColumns && draggedColumn && pinnedColumns.length <= 0"