test(zone.js): should invoke XHR task even onload handler throw error. (#41562)

Close #41520.

This case related to the issue #41522.

```
Zone.root
  .fork({
    name: 'xhr',
    onHasTask(delegate, currentZone, zone, taskState) {
      console.log('hasMacrotask', taskState.macroTask);
      return delegate.hasTask(zone, taskState);
    },
  })
  .run(() => {
    const xhr = new XMLHttpRequest();
    xhr.open('GET', 'https://cdnjs.cloudflare.com/ajax/libs/zone.js/0.11.4/zone.min.js');
    xhr.addEventListener('load', () => {
      throw new Error();
    });
    xhr.send();
  });
```

zone.js invoke all `onload` event handlers before change the XHR task's state from
`scheduled` to `notscheduled`, so if any `onload` listener throw error, the XHR task
wlll be hang to `scheduled`, and leave the macroTask status in the zone wrongly.

This has been fixed in the previous commit, this commit add test to verify the case.

PR Close #41562

packages/zone.js/test/browser/XMLHttpRequest.spec.ts

@@ -103,6 +103,77 @@ describe('XMLHttpRequest', function() {
     req!.send();
   });
 
+  it('should run onload listeners before internal readystatechange', function(done) {
+    const logs: string[] = [];
+    const xhrZone = Zone.current.fork({
+      name: 'xhr',
+      onInvokeTask: (delegate, curr, target, task, applyThis, applyArgs) => {
+        logs.push('invokeTask ' + task.source);
+        return delegate.invokeTask(target, task, applyThis, applyArgs);
+      }
+    });
+
+    xhrZone.run(function() {
+      const req = new XMLHttpRequest();
+      req.onload = function() {
+        logs.push('onload');
+        (window as any)[Zone.__symbol__('setTimeout')](() => {
+          expect(logs).toEqual([
+            'invokeTask XMLHttpRequest.addEventListener:load', 'onload',
+            'invokeTask XMLHttpRequest.send'
+          ])
+          done();
+        });
+      };
+      req.open('get', '/', true);
+      req.send();
+    });
+  });
+
+  it('should invoke xhr task even onload listener throw error', function(done) {
+    const logs: string[] = [];
+    const xhrZone = Zone.current.fork({
+      name: 'xhr',
+      onInvokeTask: (delegate, curr, target, task, applyThis, applyArgs) => {
+        logs.push('invokeTask ' + task.source);
+        return delegate.invokeTask(target, task, applyThis, applyArgs);
+      },
+      onHasTask: (delegate, curr, target, hasTaskState) => {
+        if (hasTaskState.change === 'macroTask') {
+          logs.push('hasTask ' + hasTaskState.macroTask);
+        }
+        return delegate.hasTask(target, hasTaskState);
+      }
+    });
+
+    xhrZone.run(function() {
+      const req = new XMLHttpRequest();
+      req.onload = function() {
+        logs.push('onload');
+        throw new Error('test');
+      };
+      const unhandledRejection = (e: PromiseRejectionEvent) => {
+        logs.push(e.reason.message);
+      };
+      window.addEventListener('unhandledrejection', unhandledRejection);
+      req.addEventListener('load', () => {
+        logs.push('onload1');
+        (window as any)[Zone.__symbol__('setTimeout')](() => {
+          expect(logs).toEqual([
+            'hasTask true', 'invokeTask XMLHttpRequest.addEventListener:load', 'onload',
+            'invokeTask XMLHttpRequest.addEventListener:load', 'onload1',
+            'invokeTask XMLHttpRequest.send', 'hasTask false',
+            'invokeTask Window.addEventListener:unhandledrejection', 'test'
+          ]);
+          window.removeEventListener('unhandledrejection', unhandledRejection);
+          done();
+        });
+      });
+      req.open('get', '/', true);
+      req.send();
+    });
+  });
+
   it('should return null when access ontimeout first time without error', function() {
     let req: XMLHttpRequest = new XMLHttpRequest();
     expect(req.ontimeout).toBe(null);