Turn on MassUpload splitDocuments UI

[finishes #60788560]
Split FileGroup Processing between text extraction and clustering
Split out helpers from test class file
Start clustering when text extraction is done
Split Job into tasks which are handed to workers
Extract test actor into separate file
Extract methods
Remove use of TestActorRef
Register with JobQueue on startup
Add some constants
Execute task steps
Add text to page
Submit jobs to clustering workers
Forward messages to actor handling processing of uploads
Add new command for upload clustering
Use new upload clustering command
Submit job by setting state to NotStarted
Set document set name
Implement storage functions
Use new workers for processing uploads