Audit and better document the useNavigationMenu hook

[afercia]

Description

Splitting this out from #67009 see relevant discussion there together with @ntsekouras and @draganescu

It appears there is some uncertainty about this hook expected behavior and that's in part because it is not documented at all.

From the conversation starting from
#67009 (comment) a few main points emerge:

• No one seems to recall why passing the Id is optional
  • It is worth noting that some of the returned values are different based on whether the ID is passed or not. For example, when the ID is not passed, isNavigationMenuMissing is assumed to be true which is confusinga not necessarily always true.
• It's unclear whether menuUnavailable is working as intended or buggy.
• This test seems to indicate that when the ID is not passed, then useNavigationMenu returns information about all menus while instead, when the ID is passed, it returns information about a specific menu. To my understanding, that's not entirely true as it seems to me this hook returns information about all menus anyways.

Overall, it seems there's some room for improvements. At the very least, some documentation should clarify this hook usage.

Step-by-step reproduction instructions

N/A

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[Vrishabhsk]

Hi @afercia 👋

• I have raised the PR : Feat : Improve Docs for useNavigationMenu hook #68499

Let me know your thoughts. Thanks