What

This PR refactors the Navigation Link and Navigation Submenu blocks to reduce code duplication by extracting shared inspector controls functionality into a reusable component.

Supports #71630

Why

Supporting Dynamic URL Functionality

This refactoring is a prerequisite for integrating the Dynamic URL functionality developed in PR #71630. The Dynamic URL feature uses the Block Bindings API to make Navigation Link URLs dynamic when linking to entities (Pages, Posts, etc.), ensuring links don't break when permalinks change.

Code Quality Improvements

• Reduce code duplication - Eliminate identical code between Navigation Link and Navigation Submenu blocks
• Ensure consistency - Both blocks now use the same components, preventing behavioral differences
• Reduce maintenance burden - Changes to shared functionality only need to be made in one place
• Minimize bugs - Less duplicated code means fewer places for bugs to hide
• Improve testability - Shared components can be tested once and reused

How

Created a shared Controls component that encapsulates the common ToolsPanel functionality used by both navigation blocks. The component maintains all original functionality including URL handling, entity link management, and user interactions.

Testing

1. Inspector Controls (Settings Panel)

• Select either block → Open Settings panel (gear icon)
• Test each control:
  • Text: Enter text, verify it appears, test HTML stripping
  • Link: Enter URL, verify encoding/decoding works
  • Open in new tab: Check/uncheck, verify behavior
  • Description: Enter text, verify it appears
  • Rel attribute: Enter values like "nofollow", verify they're applied
• Test Reset: Click Settings options (three dots) → Reset → verify all fields clear

2. Entity Link Handling

• Click Link Control → Search and select a Page/Post
• Verify URL auto-populates and works on frontend

3. Frontend Verification

• Save menu → View frontend
• Verify links work correctly
• Test "Open in new tab" functionality
• Verify descriptions appear (if theme supports)

4. Cross-Block Testing

• Create menu with both Navigation Link and Submenu blocks
• Verify both blocks work identically
• Test submenu expand/collapse functionality

5. Regression Testing

• Load existing menus with these blocks
• Verify they still work without data loss
• Test with different themes

Future Direction

This refactoring prepares the foundation for:

1. Dynamic URL Integration - Easy integration of the Block Bindings API functionality from PR Navigation Link: Use block bindings to dynamically fetch the URL in the editor and on front end.  #71630
2. Unified Navigation Item Block - Long-term vision of a single block that adapts based on context
3. Consistent Feature Rollout - New features can be added to both blocks simultaneously

Backward Compatibility

• No breaking changes to existing functionality
• All original behavior preserved
• Both blocks maintain their current APIs and user experience