List requests and their progress

Return your organization's requests, newest first, as the dashboard's progress page shows them.

**Query parameters:**
- `submission_id`: return only this request
- `before`: an ISO 8601 time; return the page of requests made before it

**Each request includes:**
- `id`, `submittedAt`, `completedAt`
- `stage`: `received`, `testing`, `verifying` or `complete`
- `progress`: `overall`, `tested` and `verified` as percentages
- `minutesLeft`: estimated minutes left in the current stage, when known
- `build`: label and OS of the app build
- `testCases`: the test cases requested
- `bugs`: verified bugs found
- `notCovered`: test cases that could not be covered, with a note
- `cancelled`, `delayed`, `delayReason`
- `canCancel`: whether `POST /v1/missions/submissions/{id}/cancel` would be accepted