Add Tagify module and set it as default widget for entity reference fields

Problem/Motivation

#3511946: Enable Tagify in the admin_ui and content_type_base recipes, and use it on all reference fields defined by our content types
Moving with Drupal CMS's adopted module
https://www.drupal.org/project/drupal_cms/issues/3511946#comment-16022260
https://www.drupal.org/project/drupal_cms/issues/3511946#comment-16024915

Tagify sounds like a great choice! we are maintaining the Autocomplete Deluxe module, but we're leaning towards switching from Autocomplete Deluxe to Tagify.

Proposed resolution

• Add drupal/tagify ~1 to the composer.json file.
• Enable Tagify by default, and set Tagify as the default widget for all entity reference field types.
• See also #3537129: Switch Tags field widget from Autocomplete Deluxe to Tagify for the Blog post content type
• Do not enable the Autocomplete Deluxe module for new installations
• Remove Autocomplete Deluxe from Varbase 11, but retain it in Varbase 10.1.x for compatibility and smoother upgrade paths

Remaining tasks

• ✅ File an issue about this project
• ✅ Addition/Change/Update/Fix to this project
• ✅ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ✅ Developer Documentation support on feature change/addition
  

  Added Tagify to Varbase Core doc page

• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ✅ Code review from 1 Varbase core team member
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Update Release Notes and Update Helper on new feature change/addition
• ✅ Release varbase-10.1.0-alpha2, varbase_core-10.1.52

Varbase update type

• ✅ No Update
• ➖ Optional Update
• ➖ Forced Update
• ➖ Forced Update if Unchanged

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Issue #3537130: Added Tagify module and set it as default widget for entity reference fields