Fixes#1968
Changes:
- `stopped_quota_reached` and `skipped_quota_reached` migrated to new
values that indicate which quota was reached
- Before crawls are run, the operator checks if storage or exec mins
quotas are reached and if so fails the crawl with the appropriate state
of `skipped_storage_quota_reached` or `skipped_time_quota_reached`
- While crawls are running, the operator checks if the exec mins quota
is reached or if the size of all running crawls will mean the storage
quota is reached once uploaded; if so, the crawl is stopped gracefully
and given `stopped_storage_quota_needed` or `stopped_time_quota_reached`
state as appropriate
- Adds new nightly tests for enforcing storage quota
