rpc: Added totalSigs to JSON response for scriptToJSON

- Added totalSigs property to the JSON response object
- Use getMultisig() function to return n value if available

lib/node/rpc.js

@@ -2984,17 +2984,21 @@ class RPC extends RPCBase {
       hex: undefined,
       type: Script.typesByVal[type],
       reqSigs: 1,
+      totalSigs: 1,
       p2sh: undefined
     };
 
     if (hex)
       json.hex = script.toJSON();
 
-    const [m] = script.getMultisig();
+    const [m, n] = script.getMultisig();
 
     if (m !== -1)
       json.reqSigs = m;
 
+    if (n !== -1)
+      json.totalSigs = n;
+
     return json;
   }