Prop 156: [SIPS-143] Real Yield BTC Cellar Incentives

This proposal is intended to authorize a one-time transfer of 100,000 SOMM from the community pool to the CellarStaking contract, which is used to incentivize Real Yield BTC cellar depositors on Ethereum Mainnet.

See the corresponding forum post for more details: https://community.sommelier.finance/t/sips-143-upcoming-real-yield-btc-liquidity-mining-incentives-proposal/1307