Add XNAT as an endpoint

[p-j-smith]

Description

Fixes #471

• add a new class core.uploader._orthanc.StudyTags to hold relevant info for a study to be uploaded
• add a new class core.uploader._xnat.XNATUploader to upload a zipped DICOM study to XNAT using XNATPy
• add a test to check we can upload data to XNAT. Uses xnat4test to spin up a docker container with a test XNAT instance. The test data is based on test data from the integration tests.

Type of change

Please delete options accordingly to the description.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Suggested Checklist

• [X] I have performed a self-review of my own code.
• [X] I have made corresponding changes to the documentation.
• [ ] My changes generate no new warnings.
• [X] I have commented my code, particularly in hard-to-understand areas.
• [X] I have passed on my local host device. (see further details at the CONTRIBUTING document)
• [X] Make sure your branch is up-to-date with main branch. See CONTRIBUTING for a general example to syncronise your branch with the main branch.
• [X] I have requested PR review to UCLH-Foundtry/arc-dev
• [ ] I have adddressed and marked as resolved all the review comments in my PR.
• [ ] Finally, I have selected squash and merge

Here's the scans uploaded to XNAT by the test:

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 84.56376% with 23 lines in your changes missing coverage. Please review.

Project coverage is 84.89%. Comparing base (34cf403) to head (b84c826). Report is 1 commits behind head on main.

Files	Patch %	Lines
pixl_core/src/core/uploader/_xnat.py	53.12%	15 Missing :warning:
pixl_core/src/core/uploader/_ftps.py	0.00%	2 Missing :warning:
pixl_core/tests/uploader/test_xnat.py	97.10%	2 Missing :warning:
pixl_core/src/core/uploader/_dicomweb.py	66.66%	1 Missing :warning:
pixl_core/src/core/uploader/_orthanc.py	87.50%	1 Missing :warning:
pixl_core/src/core/uploader/base.py	90.90%	1 Missing :warning:
pixl_export/src/pixl_export/main.py	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #483 +/- ## ========================================== + Coverage 83.31% 84.89% +1.57% ========================================== Files 80 86 +6 Lines 3374 3753 +379 ========================================== + Hits 2811 3186 +375 - Misses 563 567 +4 ```

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[p-j-smith]

It looks good to me. I wonder if it is useful to add some details or links in relevant README files on how to connect to xnat (which might solve few of my comments?).

Thanks for the review! Yeah good point, I'll add some info on how to connect to XNAT and login

[p-j-smith]

Thanks for the reviews, and for making sure the tests run properly!