Add x-arrow attribute to popover arrow element so PopperJS will apply the right styling

Author: VishaalK

src/scripts/clipperUI/components/popover.tsx

@@ -71,6 +71,7 @@ class PopoverClass extends ComponentBase<{}, PopoverProps> {
 			for (let i = 0; i < this.props.arrowClassNames.length; i++) {
 				arrowElement.classList.add(this.props.arrowClassNames[i]);
 			}
+			arrowElement.setAttribute("x-arrow", "");
 			popperElement.appendChild(arrowElement);
 		}