Function compare_key_setups 

fn compare_key_setups(
    key_id: &KeyId,
    namespace: Option<&NamespaceId>,
    key_setup_a: KeySetupComparison,
    key_setup_b: KeySetupComparison,
)

Compares the key setups of a key from a Signstar config and that of a NetHSM backend.

Compares the KeyType and KeyMechanisms of key_setup_a and key_setup_b, which both have to be identical.

Emits a warning if the KeyType or list of KeyMechanisms of key_setup_a and key_setup_b do not match.