[code-quality] Add DirectInstanceOverMockArgRector

[TomasVotruba]

Based on PHPUnit 12, I've noticed some classes are mocked, but only passed allong as objects.
It doesn't bring any value, esp. for simple objects like Request and RequestStack

use PHPUnit\Framework\TestCase;
use Symfony\Component\HttpFoundation\Request;

final class SomeTest extends TestCase
{
    public function test()
    {
-        $this->someMethod($this->createMock(Request::class));
+        $this->someMethod(new Request());
    }

    private function someMethod($someClass)
    {
    }
}

[samsonasik]

->isFirstClassCallable() should be checked early before ->getArgs()

[samsonasik]

I created PR

• [PHPUnit 12] Skip First class callable on DirectInstanceOverMockArgRector #610

for it.