Replace the ECA-based duplicate workflow with a native ConfirmFormBase...
Replace the ECA-based duplicate workflow with a native ConfirmFormBase implementation. This resolves the version conflict with Drupal CMS 2.0 (eca ^2.1 vs ^3.0.8).
- Add AiContextItemDuplicateForm using createDuplicate()
- Add duplicate-form link template and route
- Add Duplicate operation to list builder
- Remove eca:eca_content, eca:eca_misc, eca:eca_render dependencies
- Remove drupal/eca from composer.json
- Delete ECA workflow config
- Add update hook to clean up ECA config on existing installs
- Remove ECA modules from kernel test
Closes #3577426