Wrapper function to download image data to a local directory

[mfs4rd]

Made on request from @smishra3

[pgarrison]

@smishra3 @mfs4rd how does this fit in to our instructions for external users? Is this part of our recommended way to access the EMT data? If so, we'll need to document the purpose more clearly for an external audience (may be in a separate PR). If not, I wonder if this code belongs in another repo.

[pgarrison]

Answer from @smishra3 in person:

• The image analysis code expects OME TIFFs but we published OME Zarrs. This is the short-term solution for running image analysis code from published data.
• Long term solution is to update the image analysis code to read Zarrs
  • BUT the cellprofiler does not know how to read Zarrs, so converting Zarrs to TIFFs will remain the long-term solution for that one part of image analysis