Add job.duration in web ui (#23963)

![image](https://user-images.githubusercontent.com/18380374/230532947-271ac389-8134-4c5e-8f2f-ced4a4fd0ebe.png)

![image](https://user-images.githubusercontent.com/18380374/230532963-e76532c5-7ca1-4b01-ae77-cc1223350fe7.png)

Maybe we can change the location of it.

routers/web/repo/actions/view.go

@@ -75,6 +75,7 @@ type ViewJob struct {
 	Name     string `json:"name"`
 	Status   string `json:"status"`
 	CanRerun bool   `json:"canRerun"`
+	Duration string `json:"duration"`
 }
 
 type ViewCommit struct {
@@ -144,6 +145,7 @@ func ViewPost(ctx *context_module.Context) {
 			Name:     v.Name,
 			Status:   v.Status.String(),
 			CanRerun: v.Status.IsDone() && ctx.Repo.CanWrite(unit.TypeActions),
+			Duration: v.Duration().String(),
 		})
 	}