Add test file with a non byte-aligned segmentation

[CPBridge]

Describe the changes

Add a new test file that is a binary, natively encoded segmentation (with BitsAllocated=1) whose frames contain a number of pixels that are not a multiple of 8. Such files are valid but tricky to deal with because of the misalignment of the frame and byte boundaries.

Partial fix for pydicom/pydicom#2134

Tasks

• In a branch on your fork of pydicom-data, add or modify data files
• Create a pull request for pydicom-data
• Update the commit hash for the urls in a fork/branch of the pydicom file [urls.json]https://github.com/pydicom/pydicom/blob/master/pydicom/data/urls.json and create a pydicom pull request
• pydicom unit tests passing
• Documentation updated (if needed)

[CPBridge]

I should mention that to create this I took the existing liver image (originally 512 x 512) and just cropped it down to a "weird" size (510 x 511) and correctly re-encoded the pixels with bit-packing.