Add support for custom taxonomies in navigation editor

[spacedmonkey]

What problem does this address?

Follow up from #34440.

The current menu screen, allows for custom taxonomies terms to be added to menu. See screenshot from current editor.

However these custom taxonomies are not reflected in navigation editor.

What is your proposed solution?

Add support for custom taxonomies in navigation editor

[kathrynwp]

Closing this issue due to the Navigation Screen project being moved to an inactive status on the feature projects page in coordination with the project leads. (The developer documentation in the initial post are no longer accessible)

If this work is picked back up, issues can be revisited and reopened as needed. Thanks for pitching in on this early feature so the wider WordPress project could benefit from the lessons learned!