[ LinkControl ] Implement enhanced inline page creation flow

[sarthaknagoshe2002]

What?

Closes #72626

Adds the enhanced page creation flow (previously exclusive to the Navigation block) to the global LinkControl component with additional improvements.

Why?

The previous inline creation flow was confusing, it instantly created a draft page without confirmation and offered no control over the title or status. This aligns the default LinkControl with the superior UX currently found in the Navigation Link block.

How?

• Added LinkControlPageCreator which asks the user for the "holy trinity" of quick page creation: Title, URL Slug (dynamically auto-populated as you type), and Status (Publish/Draft).
• Delegated the actual saveEntityRecord database call back up to the block consumers (e.g., Button/Edit.js, inline.js) via onCreateSuggestion.
• Disabled the old inline creation dropdown item when the new dedicated bottom button is active to prevent duplicate UI elements.
• The old legacy controls can be still used by passing showCreateSuggestionInDropdown as true.

Testing Instructions

1. Open a post or page in the editor.
2. Add a Button block, or highlight text in a Paragraph and press Cmd/Ctrl + K.
3. Type a non-existent page name in the link search box.
4. Click the new + Create page button at the bottom of the popover.
5. Verify the new sub-view that opens and the Title is pre-populated.
6. Verify the URL Slug auto-populates with a leading slash (e.g., /my-page) as you type, unless manually edited.
7. Toggle the "Publish immediately" checkbox, click "Create", and verify the link is applied and the page was created in the backend with the correct status and slug.

Screenshots or screencast

Before	After

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