Add DICOM QR SCU Scheduled Tasks

[Ed McDonagh]

Use Celery Beat to schedule QR tasks to regularly get new data from a PACS or similar

[Ed McDonagh]

Added database ID to the remote QR node listings. Refs #261

→ <<cset edb4f35852ce>>

[Ed McDonagh]

Implemented a command line query-retrieve function that could be called from a cron job or task manager. Limited testing. Needs a script and documentation. Refs #261

→ <<cset dbb18be6b95a>>

[Ed McDonagh]

Clarified the help text for the duplucates argument. Refs #261

→ <<cset ece11f3c7eda>>

[Ed McDonagh]

Adding script for QRSCU. Refs #261

→ <<cset 9fc55859d304>>

[Ed McDonagh]

Celery no longer in use (v1.0 and later), so Celery Beat is not the answer to this one. Instructions for crontasks and Windows scheduler exist, but need to be updated to use both Docker and non-docker.

Leave issue here as a future aspiration but don’t currently see how it would work within the web interface on both Windows and Linux (and Docker).