Publish crate and python wrapper

[andrewwhitehead]

The current python wrapper lives in https://github.com/mattrglobal/ffi-bbs-signatures so it would be best to submit PRs there.

This crate should be published to crates.io (after testing the wrapper integration), and the wrapper crate updated to support linux/arm64. The main build script is at https://github.com/mattrglobal/ffi-bbs-signatures/blob/master/scripts/build.sh, where the Linux section might be updated to generate two different libraries. Currently, it doesn't appear that Cross is used, which makes me wonder whether the wrapper is actually manylinux2014 compatible. It might be good to borrow from https://github.com/hyperledger/indy-shared-rs/blob/main/.github/workflows/build.yml for checking this compatibility. It would also be useful to extend the MacOS build to create a universal binary, as it appears to be x86_64 only (supported via rosetta 2) at the moment.

[esune]

On hold until a new BBS strategy is available to be implemented.