Add Batch feature (XLS-56) (#5060)

- Specification: [XRPLF/XRPL-Standards 56](https://github.com/XRPLF/XRPL-Standards/blob/master/XLS-0056d-batch/README.md)
- Amendment: `Batch`
- Implements execution of multiple transactions within a single batch transaction with four execution modes: `tfAllOrNothing`, `tfOnlyOne`, `tfUntilFailure`, and `tfIndependent`.
- Enables atomic multi-party transactions where multiple accounts can participate in a single batch, with up to 8 inner transactions and 8 batch signers per batch transaction.
- Inner transactions use `tfInnerBatchTxn` flag with zero fees, no signature, and empty signing public key.
- Inner transactions are applied after the outer batch succeeds via the `applyBatchTransactions` function in apply.cpp.
- Network layer prevents relay of transactions with `tfInnerBatchTxn` flag - each peer applies inner transactions locally from the batch.
- Batch transactions are excluded from AccountDelegate permissions but inner transactions retain full delegation support.
- Metadata includes `ParentBatchID` linking inner transactions to their containing batch for traceability and auditing.
- Extended STTx with batch-specific signature verification methods and added protocol structures (`sfRawTransactions`, `sfBatchSigners`).

src/test/rpc/Simulate_test.cpp

@@ -465,6 +465,36 @@ class Simulate_test : public beast::unit_test::suite
         }
     }
 
+    void
+    testInvalidTransactionType()
+    {
+        testcase("Invalid transaction type");
+
+        using namespace jtx;
+
+        Env env(*this);
+
+        Account const alice{"alice"};
+        Account const bob{"bob"};
+        env.fund(XRP(1000000), alice, bob);
+        env.close();
+
+        auto const batchFee = batch::calcBatchFee(env, 0, 2);
+        auto const seq = env.seq(alice);
+        auto jt = env.jtnofill(
+            batch::outer(alice, env.seq(alice), batchFee, tfAllOrNothing),
+            batch::inner(pay(alice, bob, XRP(10)), seq + 1),
+            batch::inner(pay(alice, bob, XRP(10)), seq + 1));
+
+        jt.jv.removeMember(jss::TxnSignature);
+        Json::Value params;
+        params[jss::tx_json] = jt.jv;
+        auto const resp = env.rpc("json", "simulate", to_string(params));
+        BEAST_EXPECT(resp[jss::result][jss::error] == "notImpl");
+        BEAST_EXPECT(
+            resp[jss::result][jss::error_message] == "Not implemented.");
+    }
+
     void
     testSuccessfulTransaction()
     {
@@ -1081,6 +1111,7 @@ public:
     {
         testParamErrors();
         testFeeError();
+        testInvalidTransactionType();
         testSuccessfulTransaction();
         testTransactionNonTecFailure();
         testTransactionTecFailure();