Add a JPEG-LS dataset with precision 7

[scaramallion]

Describe the changes

Adds a JPEG-LS dataset with a sample precision of 7

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)