Switched from items to dataSource, added mouse leave/enter events

1. Switched to dataSource instead of items, this way the menu will automatically render nested items. Before it would not render the nested menu structure because the html was being formed manually.
1a. side effect of this is I could not get the iconCss to work and insert template correctly but you can use the ImageUrl to add images as needed.

2. Added mouse leave/enter to hide/keep showing the menu as needed