State root derived from MultiProof might diverge

[citizen-stig]

Essence of new test:

/// some key/values written before.
let (prover_root, witness) = t.commit();
let nomt::Witness {
    path_proofs,
    operations: nomt::WitnessedOperations { .. },
} = witness;
let mut inner = path_proofs.into_iter().map(|p| p.inner).collect::<Vec<_>>();
inner.sort_by(|a, b| a.terminal.path().cmp(b.terminal.path()));
let multi_proof = MultiProof::from_path_proofs(inner);

/// verify
let verified = verify_multi_proof::<Blake3Hasher>(&multi_proof, prev_root)
    .expect("multiproof must verify against the prior root");

let mut updates: Vec<(KeyPath, Option<ValueHash>)> = accesses
    .iter()
    .filter_map(|(k, op)| match op {
        KeyReadWrite::Write(v) | KeyReadWrite::ReadThenWrite(_, v) => {
            Some((*k, v.as_deref().map(Blake3Hasher::hash_value)))
        }
        KeyReadWrite::Read(_) => None,
    })
    .collect();
updates.sort_by(|a, b| a.0.cmp(&b.0));

let verifier_root = verify_multi_proof_update::<Blake3Hasher>(&verified, updates).unwrap();
assert_eq!(prover_root, verifier_root);