Auto-remove processed records

[nivemaham]

processed records can be removed from backend to free up some space.

[blootsvoets]

Note: an extension to this class could be made for that purpose: https://github.com/RADAR-base/radar-upload-source-connector/blob/master/radar-upload-backend/src/main/java/org/radarbase/upload/lifecycle/RecordStateLifecycleManager.kt