Added support for the 8-player layout for UPF matches.

Fixed a bug with the playmat placement.

- Visual updates for card containers
- Added CRU preview art for playmats
- Minor UX tweaks for playmat selection

- Customization of the background can be done through the "Lock" UI as well now.
- Added custom objects for the hero decks.

- The 'All Cards' deck was completely rebuilt. Changes include:
- All variations are cards are now available (e.g. promos, hero deck cards, etc.)
- All cards have their proper identifier in their description (this allows you to build decks with alternate versions of cards with the same name)
- Image sheets are more compact making for a smaller download
- Playmats have their snap points restored
- Playmat image can be easily cycled now. Press the "Lock" button in the "Layouts" bar at the top of the screen to configure any given mat.

- Updated sideboard loading based on FaB DB API changes
- Added a "Lock" button toggle the interactability of the playmats (this prevents accidental ALT-zooming)

- Rebuilt the deck builder. It now supports FaB DB's API.
- Added 2 and 4 player layouts.
- Playmats now select a random image when added (specific playmats can be chosen from the bags).