[DataGrid] Fix issue #5026 (from Aspire) (#5028)

* - Extend a11y support for typical example by supplying HeaderTooltip valies
- Add HeaerTooltip, aria-haspopup="menu and title to button in column header
- Return null for aria-sort if not sorted
- Set menu aria-expanded in script so it can cleanly be set when dismissed by overlay click

* Update verified files

* Tweak new behavior, add back aria-sort="none"

* Process comment

* Fix veriefied files