Drag and drop - drop zone styling

[kmcfaul]

Part of the ongoing drag and drop improvements, do we want to add specific drop zone styling for multiple drop zones (patternfly/patternfly-react#10614 adds this feature)?

The old drag and drop had a red/blue border around the zone based on where the item was hovered. However, the new solution can drag complex components like DualListSelector and DataList and those components' styling may interfere, so we may have to design separate styles per draggable component.