Implement support for DICOM WSI

[HarmvZ]

Part of https://github.com/DIAGNijmegen/rse-roadmap/issues/217

• Adds the dcm_to_tiff code from the pitch as an internal dependency, the code is unchanged except for some styling done by the pre-commit hooks.
• Adds wsidicom and imagecodecs dependencies. wsidicom requires a slightly more strict Python version until https://github.com/imi-bigpicture/wsidicom/pull/96 is merged.
• For the tests I've used some test files generated by code from wsidicom. I've also tested locally with some publicly available data from the medical.nema.org FTP server described here. I'm not sure what the usage restrictions are on that data. We could include it in our tests to have more realistic data if that is allowed.

[HarmvZ]

These builds are now failing because of the same urllib issue as in https://github.com/DIAGNijmegen/rse-panimg/pull/95. Let's merge that first to fix the issue.