Clearer deck cards and a popup for deck details

Deck cards in a playgroup's Decks tab now show the deck's chosen card art and its color identity as their own little boxes next to the name, owner, and format, instead of a single small icon. It's easier to spot the deck you're looking for at a glance. Opening a deck also works differently now. Instead of expanding a panel at the bottom of the page, clicking a deck opens its details in a popup right in the middle of your screen. Close it by clicking outside the popup, pressing Escape, or the Close button.