[wip] moving from cloudpickle to dill

[djarecka]

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Summary

checking dill as suggested in #260

unfortunately it doesn't look like that dill helps with the checksum in various os

Checklist

• All tests passing
• I have added tests to cover my changes
• I have updated documentation (if necessary)
• My code follows the code style of this project
  (we are using black: you can pip install pre-commit,
  run pre-commit install in the pydra directory
  and black will be run automatically with each commit)

Acknowledgment

• I acknowledge that this contribution will be available under the Apache 2 license.

[satra]

not directly through pickle perhaps but via source code? the question is how to get source code of all dependencies in __main__

[ghisvail]

Is it still worth keeping this PR open?