We need to create articles bulk ingestion `articles` endpoint to ingest pages from all the the projects that we support so that we can then use that data for On-demand and Snapshots service.
**Acceptance criteria**
I can trigger articles endpoint for a project name and ingest all of the articles in that project.
**To-Do**
[ ] add `articles` method to `bulk.proto` in `protos` repository
[ ] add `articles` handler to `bulk-ingestion` service
[ ] input params should be a `project` and `namespace`
[ ] need to investigate if titles dump is still the best way to get a list of articles
[ ] should produce an event with list of titles to go through
[ ] implementation of `articlesbulk` handler in `structured-data` service
[ ] should produce similar outcome as `articleupdate` handler but omit versions