Include other participants' public nonces in reference tests

[nickfarrow]

Some implementations of MuSig will be easier to test if the reference contains the other party's public nonces, as opposed to the nonces having already been aggregated. If you initialize signing sessions with [nonce1, nonce2, ... ] rather than a pre-aggregated aggnonce,

The other two participants' public nonces could be aggregated within the tests themselves, or included in a comment above aggnonce = .... Or in a separate basic test for nonce_agg(). This would make both pre-aggregated and nonce-list input designs easy to test.

[jonasnick]

Good point. The public nonces are added to the test vectors in PR #9 (e.g. here).

[real-or-random]

Solved by #9.