Add Controller Status to Status

[dyaffe]

Background
We currently offer multiple locations that we surface the status of a task. It would be ideal to surface all relevant information in a single place.

Proposal

1. Update "overview" -> "shard information" to "status"
2. Surface a top level status which is a combination of "Shard Status", "Controller Status" and "source capture up to date status". If they're all green, the status should be green. If "Shard status" is green but either of the others are yellow or red, we should show red. If "Shard status" is yellow or red, we should show what it is.
3. Below the status icon, we should display warning or errors and warnings prominently, with priority going to the "Shard status" error.

The "Controller status" error should be based on the most recent controller status.