Convert AZ Navbar to be a SDC

[djcelaya]

See #5405.

Summary

Convert the AZ Navbar Twig override in az_barrio into a Single Directory Component.

This extracts the recursive navbar markup into a theme SDC, keeps the existing menu template as a thin presenter, and moves the navbar hover JavaScript into the component so the markup and behavior now live together.

Changes

• Add a new az_main_navbar SDC in themes/custom/az_barrio/components/az_main_navbar/
• Refactor menu--main-navbar-az.html.twig to render the SDC instead of owning the recursive menu macro directly
• Simplify the component API to pass plain data across the SDC boundary
• Move navbar hover behavior from a standalone theme library into az_main_navbar.js
• Remove the old az-navbar-hover library definition and obsolete JS file
• Extend AzBarrioTest to enable az_navbar during the test and verify the navbar variation and component-owned JS render correctly

Why

This continues the az_barrio SDC exploration with a more complex example than breadcrumb.

AZ Navbar was a useful next target because it exercises:

• recursive Twig rendering
• menu state handling
• component-owned JavaScript
• presenter-template integration with existing theme suggestion logic

Testing

• lando drush cr
• lando phpunit --filter AzBarrioTest

Notes

• The presenter template still serves as the entry point for the az_navbar-specific menu suggestion
• The component contract was reduced to plain data after runtime validation showed passing Drupal Attribute objects across the SDC boundary caused component validation errors
• PHPUnit still reports an unrelated existing deprecation in az_migration