feat: improve compliance framework error messages

What does this merge request do and why?

This MR enhances error message display for compliance framework creation and editing by replacing the previous single error extraction with logic that handles multiple validation errors by joining them together with proper formatting. The changes improve user experience by showing all relevant backend validation errors instead of just the first one.

Screenshots / recordings

Before:

After:

How to set up and validate locally

1. Create a compliance framework named "ABC"
2. Verify that the framework is created successfully
3. Go back and create another framework with the same name "ABC"
4. This time the creation would fail and you'll see an error message as mentioned above.

Related issues

Relates to issue #546682 (closed)

Changes

• Enhance error message display for compliance framework creation failures
• Replace generic error messages with specific backend validation errors
• Improve user experience by showing actionable error messages when framework names are duplicated
• Add better error handling for network failures vs validation failures