multi: modify listtxn definition

This commit modifies listtransactiondetails method definition to
take in additional params: index_offset and maxTxn

rpcserver.go

@@ -6477,7 +6477,8 @@ func (r *rpcServer) GetTransactions(ctx context.Context,
 	}
 
 	transactions, err := r.server.cc.Wallet.ListTransactionDetails(
-		req.StartHeight, endHeight, req.Account,
+		req.StartHeight, endHeight, req.Account, req.IndexOffset,
+		req.MaxTransactions,
 	)
 	if err != nil {
 		return nil, err