Provide Linkit plugin support in Acquia DAM

Problem/Motivation

In Media: Acquia DAM LinkIt plugin support was provided but after update to Acquia DAM I don't see the LinkIt plugin support in Acquia DAM.
LinkIt plugin support was previously available in the Media: Acquia DAM module. However, following the upgrade to the newer Acquia DAM module, this LinkIt plugin functionality has been removed or is no longer available. The legacy plugin implementation can be found at: https://git.drupalcode.org/project/media_acquiadam/-/blob/2.x/src/Plugin...

This removal creates a usability gap for content editors who rely on LinkIt's autocomplete functionality for quickly linking to Acquia DAM assets within CKEditor. Without LinkIt support, editors must manually copy and paste DAM asset URLs, which is error-prone and time-consuming.

Steps to Reproduce

• Install and enable the Acquia DAM module (newer version) in a Drupal site
• Configure LinkIt module for CKEditor integration
• Attempt to use LinkIt's autocomplete feature to search for and insert Acquia DAM assets
• Observe that LinkIt does not recognize or provide suggestions for DAM assets

Proposed resolution

Provide LinkIt plugin support in the Acquia DAM module by:

• Developing a LinkIt substitution plugin (Plugin/Linkit/Substitution/DamAsset.php) that integrates with the current Acquia DAM module architecture
• Enabling autocomplete search functionality for Acquia DAM assets within CKEditor
• Ensuring backward compatibility for sites migrating from Media: Acquia DAM 1.x to the newer Acquia DAM module