We observed some race condition errors in the conversation participation listener while trying to create a conversation participation assignment. This PR handles this error and also adds additional debug information for future.
fixes: https://linear.app/chatwoot/issue/CW-3296/activerecordrecordnotunique-pguniqueviolation-error-duplicate-key
## Changelog
- handles `ActiveRecord::RecordNotUnique, ActiveRecord::RecordInvald` errors so that they won't pollute sentry
- Adds a debug statement to log the cases
- Add previous_changes into the dispatcher so that we know the exact attribute changes which trigger `assignee_changed, team_changed` events ( would be handy in future )
9a8442fe0e