feat: add keyboard accessibility / tooltips for table header

[scottdover]

Summary:
This takes care of a number of accessiblity issues for the data viewer.

• It adds tooltips for icons, dropdowns, and column headers
• It updates the grid so that column menus can be navigated with the keyboard
• It fixes a bug where tabbing to another window and back to the table viewer caused rendering/sorting issues

Testing:

• Tested issuing/dismissing context menus with keyboard shortcuts
• Made sure tooltips displayed as expected
• Tested error case: open table, sort column, open properties from column header, tab back to table viewer, update column sorting criteria

[scottdover]

Hey @dahils . This one is ready for testing when you get a few moments :)