Remove delete_after_upload field for watch folders, files are deleted after uploading regardless,
otherwisre they are re uploaded at the next check.
Move language choices to the literals module
Remove language choices from the documents models module and use the one define in literals.py
Improve User model serializer
Add proper document creation API endpoint
Add custom post document version upload signal
Use the new post version upload signal to ensure OCR starts only when all of a new
document version pages have been created
Make the new document label optional, the backend will use the filename is none is specified