MainWP Kommentare-Extension 6.0.0

* Security: Improved input sanitization and output escaping across comment AJAX handlers to strengthen protection against unsafe data handling.
* Added: Network Activity logging support for comment actions to ensure comment-related changes are properly tracked.
* Added: New REST API controller and support files for the Comments extension.
* Updated: Refactored the Comments extension database handling with a new `MainWP_Comment_DB` wrapper to improve reliability and maintainability.
* Updated: Enhanced `MainWP_Comment_Utility` with new type, date, string, and placeholder helper methods for more consistent comment handling.
* Updated: Improved session handling and code structure in `MainWP_Comment` by introducing a singleton pattern and clearer internal documentation.
* Updated: Refined comment search and action handling for better correctness, maintainability, and long-term compatibility.
* Updated: Minor CSS, JavaScript, widget, and readme improvements.

* Updated: Changed the loading element styling to match the MainWP v6 UI for better consistency.
* Updated: Added an empty-state placeholder for pages with no data to align with the v6 UI.
* Updated: Added a disabled state to the Bulk Actions menu until one or more items are selected.

* Fixed: Issue with active PHP session detection
* Preventative: Multiple security improvements

= 4.0.6 - 6-21-2022 =
* Added: WP Nonce verification to the Go to WP Admin request for additional security