[优化] groupBy 新增一个单入参方法

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/conditions/interfaces/Func.java

@@ -187,6 +187,13 @@ public interface Func<Children, R> extends Serializable {
      */
     Children notInSql(boolean condition, R column, String inValue);
 
+    /**
+     * ignore
+     */
+    default Children groupBy(R column) {
+        return groupBy(true, column);
+    }
+
     /**
      * ignore
      */