Describe the changes

Two Secondary Capture test files have incorrect attributes within their Source Image Sequences. The attributes should be "ReferencedSOPClassUID" and "ReferencedSOPInstanceUID", but "SOPClassUID" and "SOPInstanceUID" have been incorrectly used instead. The images in question are SC_rgb_small_odd.dcm and SC_rgb_small_odd_big_endian.dcm. Strangely enough, though there are several other similar test files, the others do not have this issue (either they use the correct attributes or they do not have the SourceImageSequence).

The relevant part of the standard is Part 3 Section 10.8.

This PR simply updates the two test files to replace the incorrect attribute tags with the correct ones.

Tasks

• Unit tests added that reproduce the issue or prove feature is working
• Fix or feature added
• Code typed and mypy shows no errors
• Documentation updated (if relevant)
  • No warnings during build
  • Preview link (CircleCI -> Artifacts -> doc/_build/html/index.html)
• Unit tests passing and overall coverage the same or better