feat(accountNumber): Add account number to Account nav listing

Closes #474
![](http://i.imgur.com/seh6p.gif)

Seriously though, this was a class name that was tricky to pick out. It needed to be generic enough to work across various nav items, but specific enough to make some sort of sense. The general idea behind the name was that the design pattern is around a search/result display. I searched for accounts, and here's the account I got. Maybe 'current' doesn't make the most sense, but I'm not sure what would.