Artifacts API: Show latest artifacts first
Modify the Artifacts API endpoint to show results for latest observations first (sort by observation id). Currently the oldest artifacts are shown first, and there is no method to get to the latest artifact without enumerating all >300 pages (the total number of pages is intentionally not exposed by the API).
Add ordering to the Artifact model:
class Meta:
ordering = ['-network_obs_id']
indexes = [models.Index(fields=['-network_obs_id'])]
Provide a method for fetching the latest artifacts.