Fix rendering of TextInputMenuWidget

https://wikia-inc.atlassian.net/browse/VE-441

The change to ve.ui.MWCategoryWidget.js is something that the Foundation has already done in their latest. This was passing the CategoryWidget as the location to anchor the menu to. Omitting a container specification in the config makes TextInputMenuWidget use its input as the anchor. 

The height wasn't being properly set because it relies on a calculation of the innerHeight of the dialog, which is 0 because the html and body tags weren't getting height set to 100%. The MW Vector skin sets this, so it was never noticed before.