Add ability to respond to comments on compliance violations

Overview

This is a follow-up to #541095 (closed) which implemented the ability to show, add, delete, update, and react to comments on compliance violations.

This issue focuses on adding the ability to respond to comments (threaded discussions) on compliance violations.

Implementation tasks

• Update GraphQL query to support threaded discussions/replies
• Add UI for replying to existing comments
• Implement GraphQL mutation for creating replies to comments
• Ensure proper nesting and display of comment threads