chore(rbo,rules): separate the rule from common rbo code

dbcon/mysql/rbo_apply_parallel_ces.h

@@ -0,0 +1,30 @@
+/* Copyright (C) 2025 MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#pragma once
+
+#define PREFER_MY_CONFIG_H
+#include <my_config.h>
+#include "idb_mysql.h"
+
+#include "execplan/calpontselectexecutionplan.h"
+#include "rulebased_optimizer.h"
+
+namespace optimizer {
+  bool matchParallelCES(execplan::CalpontSelectExecutionPlan& csep);
+  void applyParallelCES(execplan::CalpontSelectExecutionPlan& csep, optimizer::RBOptimizerContext& ctx);
+}