ENH: replace non-DICOM attributes with DICOM aliases
ENH: replace non-DICOM attributes with DICOM aliases

@hmeine was concerned about readerID, sessionID and timePointID not being exactlly
the attrubutes defined by the standard, same as @pieper.

In the current iteration, all terms that are non-DICOM start from lower case as
a convention, but perhaps this is still not sufficient.

Alias in JSON-LD is preserved.

QIICR/dcmqi,QIICR/dcmqi,QIICR/dcmqi,QIICR/dcmqi,QIICR/dcmqi