Provide an action menu within a table cell

[nate-ni]

😯 Problem to Solve

In many tables used today, the action menu is provided via a perceived hack/workaround by creating a hidden cell that exposes the action menu. The desire is to allow an action menu to be included in an existing cell.

From table spec: "Provide API for adding action menu"

💁 Proposed Solution

• Design for action menu in a table #891

🤔 Open Questions

1. Should this be limited to 1 cell?
2. Should this be limited to only certain cell types (text, numeric, etc.)?

A11y Considerations

The end user should be able to open the menu with the keyboard.

🖼️ References/Prior Art

## Related PRs
- [ ] #937 
- [ ] #953 
- [ ] #956 
- [ ] #961 
- [ ] #962 
- [ ] #980
- [ ] #986 
- [ ] #1033
- [ ] https://github.com/ni/nimble/pull/1056