Change release process to add binary verification for Python and .Net client

The binaries that we release for python and .Net are not voted-on during the release process.
Hence, there is no way for a user to validate that the binary in PyPi or nuGet is actually generated from the code that was voted on by the PMC.

We need to modify our change process to add a step where we could validate the integrity of the binary that will be added to PyPi or nuGet