Handle the combination of DKG removals with re-attempts

With a DKG removal comes a reduction in the amount of participants which was
ignored by re-attempts.

Now, we determine n/i based on the parties removed, and deterministically
obtain the context of who was removd.

coordinator/tributary/src/block.rs

@@ -249,8 +249,6 @@ impl<T: TransactionTrait> Block<T> {
       }
       last_tx_order = current_tx_order;
 
-      // TODO: should we modify the verify_transaction to take `Transaction<T>` or
-      // use this pattern of verifying tendermint Txs and app txs differently?
       match tx {
         Transaction::Tendermint(tx) => {
           match verify_tendermint_tx::<N>(tx, schema.clone(), &commit) {