Generate SHA512SUM for release archives

[coreydaley]

The make release command will now generate a SHA512-SUMS.txt file that should be uploaded to github when a release is made.

Also fixed an issue with the arm64 windows release not having a zip extension.

[coreydaley]

/assign @apoorvajagtap

[coreydaley]

/assign @yselkowitz
Would you mind reviewing this pull request?

[apoorvajagtap]

/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: apoorvajagtap, coreydaley

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