feat(hrm): 添加流程实例任务查询功能

- 在HrmFlowInstanceController中新增getTasksByInstanceId接口
- 在HrmFlowInstanceService及其实现类中添加getTasksByInstanceId方法
- 注入UserService用于获取用户昵称信息
- 查询流程任务时关联查询处理人昵称并返回给前端
- 添加assigneeNickName字段到HrmFlowTaskVo用于显示用户昵称

fad-hrm/src/main/java/com/ruoyi/hrm/controller/HrmFlowInstanceController.java

@@ -9,6 +9,7 @@ import com.ruoyi.common.enums.BusinessType;
 import com.ruoyi.hrm.domain.bo.HrmFlowInstanceBo;
 import com.ruoyi.hrm.domain.bo.HrmFlowStartBo;
 import com.ruoyi.hrm.domain.vo.HrmFlowInstanceVo;
+import com.ruoyi.hrm.domain.vo.HrmFlowTaskVo;
 import com.ruoyi.hrm.service.IHrmFlowInstanceService;
 import lombok.RequiredArgsConstructor;
 import org.springframework.validation.annotation.Validated;
@@ -85,4 +86,9 @@ public class HrmFlowInstanceController extends BaseController {
     public R<Void> deleteRejectedInstance(@PathVariable @NotNull Long instId) {
         return toAjax(service.deleteRejectedInstance(instId));
     }
+
+    @GetMapping("/tasks/{instId}")
+    public R<List<HrmFlowTaskVo>> getTasksByInstanceId(@PathVariable @NotNull Long instId) {
+        return R.ok(service.getTasksByInstanceId(instId));
+    }
 }