add an optional prop to TreeNavSubMenu

[blegesse-w]

Closes #

Changes

PR adds an optional prop to TreeNavSubMenu component with a default value set to PopoverPosition.ToTheRightTop. This will give TreeNavSubMenu the ability to change the position of the popover modal.

Screenshots

Screen.Recording.2022-05-18.at.4.31.52.PM.mov

Checklist

Check all that apply

• Updated documentation to reflect changes
• Added entry to top of Changelog with link to PR (not issue)
• Tests pass
• Peer reviewed and approved
• Signed CLA (if not already signed)