nu-complete: display values

[rsteube]

Related problem

Other shells discern between the actual value being inserted and the one being displayed.
This enables shorter values for multiparts completion like paths where only the current segment is shown.
Additionally, some shells provide the ability to set the color (either by ansi escape sequence or additional parameter) to highlight specific values and paths (LS_COLORS).

Describe the solution you'd like

A way to return display values additionally to the ones to be inserted from custom completions. As well as the color if possible.

Describe alternatives you've considered

No response

Additional context and details

related #5291

[fdncred]

Most of the menu stuff is in reedline, but some is also in nushell. It would be nice to use the LS_COLORS we currently support in menus. @elferherrera where would someone go to implement this coloring change?

[elferherrera]

Sorry, can you paste an image of how you would like it to look like?

[fdncred]

The completions example above already has a screenshot, note that folders are a different color than files, etc.

[rsteube]

Here's another example with git: