Drupal 10.x compatibility for CKE4

Drupal 10 support!

• Removal of legacy Javascript support (JS builds target Chrome 60 or new)
• Removal of service and Symfony deprecated code
• Small bug fixes, and updates to composer.json, readme formatting
• Better error handling for search connector
• Strategy API to take over for StaticYamlPluginManager - better theme switching, and less overhead for singleton plugins

Going forward will be looking to clean up Javascript widgets, add tests and improve the documentation (very outdated).

Add autocomplete provider plugins to the toolshed_search functionality. Admins can pick an available autocomplete plugin to apply to search_api_fulltext fields with the search filters block.

If search_api_autocomplete support is provided, but not required.

Bootstrap 3 upgraded to Bootstrap 5.

- Issue #3288734: Add Drupal 10 compatibility
- This module version works with Drupal core ^9.2 || ^10

Added new layouts to use with Layout builder and Bootstrap 5.
Added several fixes.