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`).

include/xrpl/protocol/TxMeta.h

@@ -46,7 +46,10 @@ private:
         CtorHelper);
 
 public:
-    TxMeta(uint256 const& transactionID, std::uint32_t ledger);
+    TxMeta(
+        uint256 const& transactionID,
+        std::uint32_t ledger,
+        std::optional<uint256> parentBatchId = std::nullopt);
     TxMeta(uint256 const& txID, std::uint32_t ledger, Blob const&);
     TxMeta(uint256 const& txID, std::uint32_t ledger, std::string const&);
     TxMeta(uint256 const& txID, std::uint32_t ledger, STObject const&);
@@ -130,6 +133,27 @@ public:
         return static_cast<bool>(mDelivered);
     }
 
+    void
+    setParentBatchId(uint256 const& parentBatchId)
+    {
+        mParentBatchId = parentBatchId;
+    }
+
+    uint256
+    getParentBatchId() const
+    {
+        XRPL_ASSERT(
+            hasParentBatchId(),
+            "ripple::TxMeta::getParentBatchId : non-null batch id");
+        return *mParentBatchId;
+    }
+
+    bool
+    hasParentBatchId() const
+    {
+        return static_cast<bool>(mParentBatchId);
+    }
+
 private:
     uint256 mTransactionID;
     std::uint32_t mLedger;
@@ -137,6 +161,7 @@ private:
     int mResult;
 
     std::optional<STAmount> mDelivered;
+    std::optional<uint256> mParentBatchId;
 
     STArray mNodes;
 };