Create `Ai::JobTroubleshootEvent` model similar to `Ai::CodeSuggestionEvent`

Summary

As a base model for AI Impact - [BE] Root cause analysis users - Co... (#486523 - closed) we need to store /troubleshoot events in postgres table with 3 months retention rate.

The model and data will be used to backfill ClickHouse when it will be available for Dedicated.