LibOQS-Java will need to support passing in the Context String into the Sign API

[johngray-dev]

FIPS 204 and 205 uses a context string as part of their sign API. It was a last minute change in the final standard. Having an API to pass in this context will need to be added to this library.

In a similar vein, it doesn't look like liboqs support the context String yet at its API level. I see in this branch https://github.com/open-quantum-safe/liboqs/tree/bhe-fips204-final that the underlying sign.c in the ML-DSA algorithms support a context, but the higher level API and subsequent libOQS wrappers don't allow it to be passed in yet. It also looks like the regular sign() API just calls the sign_context() API and passes in NULL as the context. I imagine once that is all sorted out a context string can be passed into libOQS, then it will be possible to update this Java wrapper to support the context.