VID-1993 Fixed broken Selenium tests

* Need to wait for elements to appear before testing them
* Was not swapping video before trying to undo a swap

https://wikia-inc.atlassian.net/browse/VID-1993
you don't need 'this' in waitForElementByElement method. We are not using it so please remove it to have consistency inside the repo if there is no specific reason for adding this