[FEATURE] Extend the files supported for ingestion

[sarthakpati]

Is your feature request related to a problem? Please describe.

The following new file types need to be supported:

1. Radiology: 3D DICOM tomosynthesis to standards-compliant NIfTI images (as a likely extension to the GaNDLF's anonymization submodule): example images, example code (this is a private repo - request access)
2. Histology:
   a. Philips isyntax: example image, example code 1, 2
   b. DICOM: example image (download using this script), example code
   c. DSA annotations to PNG: take annotations generated using DSA along with the input WSI, and save the associated image patches and annotations; example data, example code (both need authorization)

Describe the solution you'd like

This will probably needs to be done over multiple PRs.

Describe alternatives you've considered

N.A.

Additional context

N.A.

[sarthakpati]

#959 takes care of 2 a and b