WIP - IUI Cards MF

This represents the current state of the IUI Cards Multifamily widget. Marking it as WIP since we will likely recompile and monkey with it a bit more. I ripped out some failing tests that I feel were not really worth keeping because they simply counted up various types of widgets and we'd need to update the count every time we add a new widget. @bbauer @mmitchellg5 can you guys review and let me know if you're ok with that?
add url_encode filter