feat(editor): AI assistant UX improvements (no-changelog)

[MiloradFilipovic]

Summary

AI assistant UI/UX improvements:

• Add loading indicator
• Only ask for feedback once after node execution
• Added new quick reply flow after node unsuccessfully executed during chat session
• Updated placeholder copy
• Added chat_session_id to User gave feedback event

Related Linear tickets, Github issues, and Community forum posts

Closes ADO2-55 Closes ADO2-56 Closes ADO2-76 Closes ADO2-85 Closes ADO2-86

Review / Merge checklist

• [ ] PR title and summary are descriptive. (conventions)
• [ ] Docs updated or follow-up ticket created.
• [ ] Tests included.
• [ ] PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)