Refactor tests (#33021)

1. fix incorrect tests, for example: BeanExists doesn't do assert and
shouldn't be used
2. remove unnecessary test functions
3. introduce DumpQueryResult to help to see the database rows during
test (at least I need it)

```
====== DumpQueryResult: SELECT * FROM action_runner_token ======
- # row[0]
  id: 1
  token: xeiWBL5kuTYxGPynHCqQdoeYmJAeG3IzGXCYTrDX
  owner_id: 0
...
```

routers/web/repo/issue_label_test.go

@@ -162,10 +162,11 @@ func TestUpdateIssueLabel_Toggle(t *testing.T) {
 		UpdateIssueLabel(ctx)
 		assert.EqualValues(t, http.StatusOK, ctx.Resp.Status())
 		for _, issueID := range testCase.IssueIDs {
-			unittest.AssertExistsIf(t, testCase.ExpectedAdd, &issues_model.IssueLabel{
-				IssueID: issueID,
-				LabelID: testCase.LabelID,
-			})
+			if testCase.ExpectedAdd {
+				unittest.AssertExistsAndLoadBean(t, &issues_model.IssueLabel{IssueID: issueID, LabelID: testCase.LabelID})
+			} else {
+				unittest.AssertNotExistsBean(t, &issues_model.IssueLabel{IssueID: issueID, LabelID: testCase.LabelID})
+			}
 		}
 		unittest.CheckConsistencyFor(t, &issues_model.Label{})
 	}