Add support for different gameboard layouts

[rbclark]

Currently we have added support for Design Phase flags which shows challenges in a similar form to how PentestChallenges are shown (Teams down the side, challenges across). In the future, we will be removing the PentestGame and PointGame types and going back to a singular game type, along with a singular division type, and instead implementing the logic so that all game types can operate in harmony with one another all at one time. In order to do this and not lose the Design Phase challenges functionality, we will need the ability to allow administrators to choose the gameboard layout. This would be a good time to also go ahead and add support for multiple categories as well (#122).