Adding client / docker image to serve header filter and print results

[vsoch]

docs will be added after testing is done!

[vsoch]

This will close https://github.com/pydicom/dicom-scraper/issues/3 Still remaining to do:

• [x] get testing set from /fs/DICOM
• [x] write complete docs / instructions for testing
• [x] generate testing report / send docs for feedback