insights: expose job status info over GraphQL API

Created by: slimsag

This exposes some status/progress information we can use in the Code Insights frontend to communicate to the viewer what is going on, how many points have been collected, if errors ocurred, etc.

For sure this isn't perfect, the most beautiful API, always super clear, etc. but it's a lot better than what we have right now (nothing.)

Missing tests, but it's a pretty straightforward implementation so I'm content merging it as-is (especially given the other option is for us to not have this until we get a backend engineer.)

Signed-off-by: Stephen Gutekanst [email protected]