[C++] Rename Qt5 to Qt (#9490)

* rename qt5 to qt

* rename, update

* rename qt5 to qt in the templates

* update doc

samples/client/petstore/cpp-qt/PetStore/main.cpp

@@ -0,0 +1,22 @@
+#include <QCoreApplication>
+#include <QTest>
+
+#include "PFXHelpers.h"
+#include "PetApiTests.h"
+#include "StoreApiTests.h"
+#include "UserApiTests.h"
+
+int main(int argc, char *argv[]) {
+    QCoreApplication a(argc, argv);
+    ::test_namespace::setDateTimeFormat("yyyy-MM-ddTHH:mm:ss.zzzZ");
+    PetApiTests petApiTests;
+    StoreApiTests storeApiTests;
+    UserApiTests userApiTests;
+    int failedTests = 0;
+
+    failedTests += QTest::qExec(&petApiTests);
+    failedTests += QTest::qExec(&storeApiTests);
+    failedTests += QTest::qExec(&userApiTests);
+
+    return failedTests;
+}