Finish integrating BLS into Leap main branch

[arhag]

#1071 was merged into the bls_integration branch as part of completing the BLS milestone of IF. However, a few changes still remain before the code can be merged into main:

Tasks

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1. Create a bls12-381 repository in the AntelopeIO organization to host the bls12-381 library from https://github.com/mschoenebeck/bls12-381.
2. Ensure the main branch of the bls12-381 repo contains the code from the leap branch of that https://github.com/mschoenebeck/bls12-381 which was used as a submodule for PR BLS12-381 Crypto Primitives #1071. (Ensure Groth16 references are not present.)
3. Add CICD support for the new bls12-381 repository to automatically run tests. Changes to tests may be necessary to ensure the various code paths (depending on architecture availability) are exercised in the test.
4. Update bls_integration branch in Leap to bring in updated bls12-381 library code as submodule.
5. Ensure the unit tests from the bls12-381 library also run as part of the tests that run in Leap (ensure they also run in the Leap CICD).
6. Fix libtester