FIP-89: Add additional collateral assets to Tribe Convex Fuse Pool

[JackLongarzo]

We should also add stETH to Tribe ETH Fuse Pool as suggested here.

FIP-xx: Add stETH to Tribe ETH Pool

Summary Add stETH to Tribe ETH Fuse Pool in addition to wstETH which is already in this pool. Motivation At time of writing, there are only 786 holders of wstETH but 53,560 holders of stETH. By only having wstETH in this Fuse pool, we are adding friction as the user has to wrap their position before depositing. Adding stETH into this Fuse pool would allow holders of the rebasing token to use as collateral to borrow ETH. Specification Whitelisting new collateral on the Tribe ETH Fuse Pool t…

Currently the pool supports only wstETH and ETH and could certainly benefit from supporting stETH as well.