Providing support for minting Beasts to alternate account

[loothero]

A simple use case for tournaments, is an agreement in which the people in the tournament agree that whoever gets the top score gets all of the beasts collected from all of the games.

In order to facilitate this, the tournament account will need to implement the Delegate Interface. The LS contract will see this and mint rewards to it.

There is however a complication that stems from the current thinking which is that the beasts would follow the game NFT. Said another way, if you start a game with Account A, transfer it to Account B, and then collect a Beast, it'll be minted to Account B. If Account A was a Controller account that implemented the DelegateInterface, the beast would be minted to the Admin account. This will however not be the case once the Game NFT is transferred to Account B.

I think the optimal option is to enable the owner of the game NFT to lock the address used for the collectible beasts. This would be a one-time call, set during start_game.