Navigation: Add draft status indicator and publish action - #83951

What?

Closes #67194

This PR adds a clear UI indicator and a one click publish action to the Navigation block when it references a wp_navigation post that is in a draft state.

Why?

Users frequently experience a situation where they build a menu in the editor, but it mysteriously disappears on the frontend because the underlying wp_navigation post is still a draft. Since there is currently no feedback in the editor, users often assume their theme is broken or recreate menus unnecessarily. This PR prevents that confusion by clearly surfacing the draft status and providing an immediate way to publish it.

How?

• Adds a passive, inline (Draft) text label next to the menu items in the editor canvas. It only renders when the parent block or a child inner-block is selected (isSelected || hasSelectedInnerBlock), avoiding layout flicker while users edit individual links.
• Adds a standard warning <Notice> in the sidebar explaining the draft state.
• Adds a one click "Publish" button inside the sidebar notice.
• Introduces a custom usePublishNavigationMenu hook.
• Uses speak() to announce the successful publication.

Design & Scope Decisions:

• Sidebar Action: The one click Publish action is intentionally restricted to the Inspector Controls. Adding text buttons to the Block Toolbar crowded the layout.
• Focus Loss: When a user clicks "Publish", the notice unmounts, causing focus to drop to the <body>, but the speak() function ensures the success state is properly announced to screen readers.

Testing Instructions

1. In your terminal, use WP-CLI to create a draft menu:
   wp post create --post_type=wp_navigation --post_status=draft --post_title="Test Draft Menu"
2. Open a post or the Site Editor.
3. Insert a Navigation block and select "Test Draft Menu" from the sidebar settings.
4. Select the block (or click into a child link). Verify the italicized (Draft) label appears safely next to the menu items without breaking the flex layout.
5. Look at the block settings in the sidebar. Verify the warning notice appears with the "Publish" button.
6. Click "Publish".
7. Verify the UI updates immediately and the frontend now renders the menu.

Screenshots or screencast

Canvas	Inspector panel

Use of AI Tools

This PR was authored with assistance from Gemini for architectural analysis of Gutenberg data hooks. All generated code was manually verified and tested.