Filter\File\RenameUpload: wrap move_uploaded_file to be easly mocked

As of yet, `ZendTest\Filter\File\RenameUploadTest` used `runkit_function_rename` to test the class that wraps `move_uploaded_file`.

Runkit extension is powerfull, but very old and almost no CI server has it.
If you run the tests with it, they fail because of a trivial bug in a test, not shown in Travis because it has not the extension.

I moved the blocking `move_uploaded_file` in a separate method, that is overwritten by the `ZendTest\Filter\File\RenameUploadMock`, a simple subclass to test the original class.

Runkit extension is no more needed, and no test is skipped.