Add BatchSignerTask

Uses a wrapper around AlgorithmMachine Schnorrkel to let the message be &[].

processor/src/multisigs/mod.rs

@@ -1,8 +0,0 @@
-#[allow(clippy::type_complexity)]
-#[derive(Clone, Debug)]
-pub enum MultisigEvent<N: Network> {
-  // Batches to publish
-  Batches(Option<(<N::Curve as Ciphersuite>::G, <N::Curve as Ciphersuite>::G)>, Vec<Batch>),
-  // Eventuality completion found on-chain
-  Completed(Vec<u8>, [u8; 32], N::Eventuality),
-}