fix(测试计划): 修复子测试计划实际起止时间为空的问题

--bug=1042708 --user=宋天阳 【测试计划】计划实际起止时间为空 https://www.tapd.cn/55049933/s/1533854

backend/services/test-plan/src/main/java/io/metersphere/plan/mapper/ExtTestPlanMapper.xml

@@ -74,6 +74,8 @@
         t.module_id as moduleId,
         t.type,
         t.description,
+        t.actual_start_time AS actualStartTime,
+        t.actual_end_time AS actualEndTime,
         t.pos,
         t.group_id AS parent,
         t.tags

backend/services/test-plan/src/main/java/io/metersphere/plan/service/TestPlanManagementService.java

@@ -78,6 +78,7 @@ public class TestPlanManagementService {
     public List<TestPlan> groupList(String projectId) {
         TestPlanExample example = new TestPlanExample();
         example.createCriteria().andTypeEqualTo(TestPlanConstants.TEST_PLAN_TYPE_GROUP).andProjectIdEqualTo(projectId).andStatusNotEqualTo(TestPlanConstants.TEST_PLAN_STATUS_ARCHIVED);
+        example.setOrderByClause("num desc");
         return testPlanMapper.selectByExample(example);
     }