refactor: Change Chain::broadcastTransaction param order

Make output argument last argument so it works more easily with IPC framework
in #10102, and for consistency with other methods

src/interfaces/chain.cpp

@@ -278,7 +278,10 @@ public:
         auto it = ::mempool.GetIter(txid);
         return it && (*it)->GetCountWithDescendants() > 1;
     }
-    bool broadcastTransaction(const CTransactionRef& tx, std::string& err_string, const CAmount& max_tx_fee, bool relay) override
+    bool broadcastTransaction(const CTransactionRef& tx,
+        const CAmount& max_tx_fee,
+        bool relay,
+        std::string& err_string) override
     {
         const TransactionError err = BroadcastTransaction(m_node, tx, err_string, max_tx_fee, relay, /*wait_callback*/ false);
         // Chain clients only care about failures to accept the tx to the mempool. Disregard non-mempool related failures.

src/interfaces/chain.h

@@ -154,7 +154,10 @@ public:
     //! Transaction is added to memory pool, if the transaction fee is below the
     //! amount specified by max_tx_fee, and broadcast to all peers if relay is set to true.
     //! Return false if the transaction could not be added due to the fee or for another reason.
-    virtual bool broadcastTransaction(const CTransactionRef& tx, std::string& err_string, const CAmount& max_tx_fee, bool relay) = 0;
+    virtual bool broadcastTransaction(const CTransactionRef& tx,
+        const CAmount& max_tx_fee,
+        bool relay,
+        std::string& err_string) = 0;
 
     //! Calculate mempool ancestor and descendant counts for the given transaction.
     virtual void getTransactionAncestry(const uint256& txid, size_t& ancestors, size_t& descendants) = 0;