feat(tx): Created v5 Fulcrum /tx endpoints in bch-api

test/v5/mocks/electrumx-mock.js

@@ -166,6 +166,11 @@ const txDetails = {
   ]
 }
 
+const txDetailsBulk = {
+  success: true,
+  transactions: [{ details: txDetails }]
+}
+
 const blockHeaders = [
   '010000008b52bbd72c2f49569059f559c1b1794de5192e4f7d6d2b03c7482bad0000000083e4f8a9d502ed0c419075c1abb5d56f878a2e9079e5612bfb76a2dc37d9c42741dd6849ffff001d2b909dd6',
   '01000000f528fac1bcb685d0cd6c792320af0300a5ce15d687c7149548904e31000000004e8985a786d864f21e9cbb7cbdf4bc9265fe681b7a0893ac55a8e919ce035c2f85de6849ffff001d385ccb7c'
@@ -178,6 +183,7 @@ module.exports = {
   txHistory,
   mempool,
   txDetails,
+  txDetailsBulk,
   blockHeaders,
   balances
 }