Fix block crash when Apple Maps credentials are missing.

[elvismdev]

Description of the Change

This PR fixes the issue where the Apple Maps block would crash when no credentials were configured instead of showing the credentials form.

Key changes:

• Added proper credentials check before MapKit initialization
• Ensured block transitions from loading state to credentials form when no credentials exist

Closes #232

How to test the Change

1. Create a new post
2. Add the Apple Maps block
3. Verify that instead of crashing, you see the credentials form with instructions

Changelog Entry

Fixed - Block crash when no Apple Maps credentials are configured, now properly shows credentials form

Credits

Props @elvismdev

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added Critical Flows, Test Cases, and/or End-to-End Tests to cover my change.
• All new and existing tests pass.

[github-actions]

@elvismdev thanks for the PR! Could you please fill out the PR template with description, changelog, and credits information so that we can properly review and merge this?

[peterwilsoncc]

Thanks for the PR, @elvismdev

While testing the code, it appears that using the settings endpoint prevents contributors and other low privileged users from using the maps block when credentials are saved.

Develop branch	PR Branch

I think the check needs to be against the MapsBlockApple/v1/GetJWT endpoint API endpoint and if that returns an error we display the unauthenticated version of the block. If it returns a valid response, the authenticated version is shown.

The endpoint is registered in the file includes/rest-routes.php