Prop 397: Gravedigger 2/2 - staking contract

this will upload the feesplit contract https://github.com/pfc-developer/steak-contracts , which is fully described in https://gov.injective.network/discussion/17238-deploy-backbones-gravedigger-lsd-on-injective. It has been audited twice, and is running on multiple mainnets already. This and the other upload proposal was written by PFC