DICOMStackToTIFF.py does not handle missing required tags

[tlancon]

For example, see here.

For an example dataset I fixed the SamplesPerPixel tag, but it was still missing other tags. This could mean that for incorrectly saved DICOM images, there must be a robust way to determine these tags, or a way to turn off these checks when reading the data.

Not critical for now as ImageJ is a good workaround.