Add Spirit-Force Milestones for Rarity Points

This proposal is to add milestones in spirit-force size which in turn modifies the Gotchi-specific trait. This can add or subtract to the specific trait of the Gotchi.

For example, in a USDC Gotchi, the following could be introduced:

1000 USDC = -1 SPK 10000 USDC = -2 SPK 100000 USDC = -3 SPK 1000000 USDX = -4 SPK

Whilst in a DAI Gotchi

1000 USDC = +1 NRG 10000 USDC = +2 NRG 100000 USDC = +3 NRG 1000000 USDX = +4 NRG

(Actual values are to be decided on separately)

By doing this we are incentivising keeping the aTokens in the Gotchi. Mini-games alone will not be sufficient as one can simply just add before the game, and then remove after.