WIP feat: add DataObjectGroup on all [Binary|Physical]DataObject descendents of DataObjectPackage.

XXX choice options are different depending on BinaryDataObject/PhysicalDataObject cardinality

branch : seda21
5 jobs for topic/seda21/eac_downgrade in 48 seconds (queued for 7 seconds)
Name Stage Failure
flake8 Lint
ERROR: InvocationError for command /builds/cubicweb/cubes/seda/.tox/flake8/bin/flake8 . (exited with code 1)
___________________________________ summary ____________________________________
ERROR: flake8: commands failed
Uploading artifacts for failed job
gl-code-quality-report.json: found 1 matching files and directories
Uploading artifacts as "codequality" to coordinator... ok
id=458592 responseStatus=201 Created token=DVC6Uz47
Uploading artifacts...
Cleaning up file based variables
ERROR: Job failed: command terminated with exit code 1