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

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.