Implement MAYO

[MAYO](https://pqmayo.org/about/) is a practical UOV variant with small key and signature sizes. It has also been submitted to Round 1 of NIST's Additional PQC Signatures.

We have finished a Go implementation, and plan to incorporate it into CIRCL.

Review the MAYO overview linked in the issue and the completed Go implementation mentioned there before examining how cryptographic schemes are incorporated into CIRCL. Done means integrating MAYO into CIRCL with the expected small key and signature sizes, with validation left to the project’s existing checks.

Written by the indexing model from the issue text.