Implement Extract task processing

**Simplified Extract work flow for archive background task**

- service is triggered
- service checks database for the last archive task
- if last unsuccessful, retry based on criteria (TODO later)
- if success, set the next query parameters and save task & task items to database
- Fetch task items and execute fetch-transform-persist operations
- update task items database records
- if failure, fail gracefully (TODO)
- when success update task database
- Emit event

Look for the archive background task service and the database models for tasks and task items. Understand the fetch-transform-persist operations and how events are emitted. The work involves setting up a new processing flow, so start by examining existing services and the data layer to see how tasks are currently managed.

Written by the indexing model from the issue text.