Remove rtc::QueuedTask alias, use webrtc::QueuedTask directly

Use absl::WrapUnique/absl::make_unique to create the queued tasks.

Bug: webrtc:10191
Change-Id: I8f47a60cb326b0fc361c7f0e338b25373d39937c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/126525
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27063}

rtc_base/task_queue_for_test.h

@@ -37,7 +37,7 @@ class RTC_LOCKABLE TaskQueueForTest : public TaskQueue {
     rtc::Event event;
     PostTask(webrtc::ToQueuedTask(
         [&task]() {
-          RTC_CHECK_EQ(false, static_cast<QueuedTask*>(task)->Run());
+          RTC_CHECK_EQ(false, static_cast<webrtc::QueuedTask*>(task)->Run());
         },
         [&event]() { event.Set(); }));
     event.Wait(rtc::Event::kForever);