Add possibility to clean PyDicom objects

[RobinFrcd]

Description

The point of this PR is to add the possibility to work on PyDicom objects directly, in order to speed up the process. It indeed avoids reading the dicom file from disk twice.

Extracting the clean_pixel_data function out of the DicomCleaner class also helps when we want to process multiple images in multiple processes without having to instance multiple DicomCleaner times (which is slow because it needs to load the recipe from disk).

Checklist

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• My code follows the style guidelines of this project

[vsoch]

I'll need to do a more thorough review after work - I'm open to the idea you've suggested here.

[vsoch]

Nice work! Let's get tests running. If all is good, the last remaining thing to do is bump the version in deid/version.py, and then write a line in the CHANGELOG.md for it.

[RobinFrcd]

@vsoch I think we're good 👍

[vsoch]

I do too! I'm in the middle of a work day so likely I'll do one final look, merge and release this evening. Stay tuned!

[vsoch]

Snuck it in :) https://pypi.org/project/deid/0.2.34/ Thank you @RobinFrcd !