Fix test-type-description-service.js flakiness (#1169)

This PR addresses test flakiness in the type description service tests by refining the asynchronous wait logic and cleaning up unused imports. Key changes include:

- Removal of the unused assertUtils import.
- Transition from a promise chain to async/await for waiting on the service and handling the response.
- Introduction of an interval-based polling mechanism to send the request and clear the timer upon response.

Fix: #1154

Author: minggangw

test/test-type-description-service.js

@@ -15,7 +15,6 @@
 'use strict';
 
 const assert = require('assert');
-const assertUtils = require('./utils.js');
 const DistroUtils = require('../lib/distro.js');
 const rclnodejs = require('../index.js');
 const TypeDescriptionService = require('../lib/type_description_service.js');
@@ -63,12 +62,15 @@ describe('type description service test suite', function () {
     const GetTypeDescription =
       'type_description_interfaces/srv/GetTypeDescription';
     const client = node.createClient(GetTypeDescription, serviceName);
-    return client.waitForService(60 * 1000).then((result) => {
-      if (!result) {
-        throw new Error('Service not available');
-      }
-      return new Promise((resolve) => {
+    const result = await client.waitForService(5000);
+    if (!result) {
+      throw new Error('Service not available');
+    }
+
+    const promise = new Promise((resolve) => {
+      const timer = setInterval(() => {
         client.sendRequest(request, (response) => {
+          clearInterval(timer);
           assert.strictEqual(response.successful, true);
           assert.strictEqual(
             response.type_description.type_description.type_name,
@@ -77,8 +79,9 @@ describe('type description service test suite', function () {
           assert.notStrictEqual(response.type_sources.length, 0);
           resolve();
         });
-      });
+      }, 2000);
     });
+    await promise;
   });
 
   it('Test type description service configured by parameter', function (done) {