feat(question-classifier): add instanceId to class-item editor

[Minamiyama]

Summary

Ensure unique editor instance when nodeId changes by generating a new instanceId

fixed #22006

Screenshots

Before	After

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

[crazywoola]

Thanks for the PR, please add my wechat crazyphage :)