feat: add batch_id to cash_in_txs

feat: bitcoind sendmany request
feat: check if wallet supports transaction batching

lib/wallet.js

@@ -210,6 +210,11 @@ function isStrictAddress (settings, cryptoCode, toAddress) {
     })
 }
 
+function supportsBatching (settings, cryptoCode) {
+  return fetchWallet(settings, cryptoCode)
+    .then(r => _.isFunction(r.wallet.sendCoinsBatch))
+}
+
 const coinFilter = ['ETH']
 
 const balance = (settings, cryptoCode) => {