campaigns: Move all worker-related funcs into single file
Created by: mrnugget
This has been bugging me for a while now so I decided to do this before changing the actual code:
- Move all worker-related code into
workers.go
- Rename
RunChangesetJobs
(plural!) toRunWorkers
- Rename
RunChangesetJob
(singular!) toExecChangesetJob
That makes finding and working on this easier.