!723 新增工作流扩展spel表达式

* update: 更新变量名称以及初始化数据 ;
* add: 新增 FlowSpel sql 脚本 ;

ruoyi-common/ruoyi-common-core/src/main/java/org/dromara/common/core/domain/dto/TaskAssigneeDTO.java

@@ -52,14 +52,14 @@ public class TaskAssigneeDTO implements Serializable {
      */
     public static <T> List<TaskHandler> convertToHandlerList(
         List<T> sourceList,
-        Function<T, Long> storageId,
+        Function<T, String> storageId,
         Function<T, String> handlerCode,
         Function<T, String> handlerName,
         Function<T, Long> groupName,
         Function<T, Date> createTimeMapper) {
         return sourceList.stream()
             .map(item -> new TaskHandler(
-                String.valueOf(storageId.apply(item)),
+                storageId.apply(item),
                 handlerCode.apply(item),
                 handlerName.apply(item),
                 groupName != null ? String.valueOf(groupName.apply(item)) : null,