Show DAML ID when hover over downarrow on SplitButton

[KirkKuykendall1]

I really like being able to hover over a button and see its DAML ID.

When hovering over the down arrow on a split button though, it would be more helpful to show the ID of the splitbutton instead of the ID of the first button within the splitbutton.

e.g. show esri_mapping_locateSplitButton instead of esri_mapping_showLocateDockPane