Remove protobuf and use parsed ORC statistics from libcudf

[bdice]

Description

This PR removes the cuDF Python dependencies on protobuf and protoc-wheel. Closes #15511.

The only use case for the protobuf dependency was reading ORC file/stripe statistics. However, we have code in libcudf that can do this without requiring protobuf.

In this PR, we expose the C++ code for parsing ORC statistics from libcudf to Cython and remove all references to protobuf.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[bdice]

A few TODO notes for myself on what I see as the weakest points of this PR. @vyasr You may have feedback on these TODOs since they're Cython related. I proposed some next steps, let me know if they sound reasonable.

[KyleFromNVIDIA]

Approving as CMake codeowner (only CMake change is deletion of a file)

[davidwendt]

Approving C++ changes

[vyasr]

Thanks for tackling this Bradley! I have a couple of small suggestions/questions.

[vyasr]

I'm heading out for a bit and I know that you want to get this in before you leave for vacation, so I'm going to go ahead and approve. It looks like all of my suggestions have been addressed other than the list comprehensions, which is just a cleanup task. Please do it if you can, but I trust that whatever version you end up with will be good enough. Thanks for this PR! Removing protobuf like this will be great.

[bdice]

/merge