Use ByteArray for Anoma cryptographic builtins

[paulcadman]

This PR adds support for ByteArray in the Anoma cryptographic functions.

builtin anoma-sign
axiom anomaSign : {A : Type} -> A -> ByteArray -> ByteArray;

builtin anoma-verify-with-message
axiom anomaVerifyWithMessage : {A : Type} -> ByteArray -> ByteArray -> Maybe A;

builtin anoma-sign-detached
axiom anomaSignDetached : {A : Type} -> A -> ByteArray -> ByteArray;

builtin anoma-verify-detached
axiom anomaVerifyDetached : {A : Type} -> ByteArray -> A -> ByteArray -> Bool;

The Anoma / Hoon Stdlib function length needs to be exposed as a StdlibFunction because a ByteArray stores its length and the value returned by anomaSign is not a fixed length.