Add rETH as collateral on v4

I would like to propose to allow rETH (optionally stETH) as collateral on mcDEX v4, rETH is decentralized staked ETH by https://rocketpool.net/

You can then go short ETH with 1x leverage on mcDEX using rETH as collateral to earn the funding rate let’s say 10% apy (taken from the average BitMex 0.01%APY every 8h), this will make your final position the same as USD.

In the end this will make it possible to earn rETH_APY+short_funding_APY~=14% APY on a stablecoin, it will be one of the best earning stablecoins on the market that is possible to scale up to large numbers and it will hopefully bring a lot of users and liquidity to mcDEX to use this strategy.