Cw20ReceiveMsgshould be a
staking_tokengiven on instantiation. The user's pending rewards and indexes are updated for each additional reward token.
reward_tokenas another reward token. A maximum of 10 reward tokens can be added.
StakerResponsefor the given staker. The pending rewards are updated to the present index.
Vec<StakerResponse>for range of stakers. The pending rewards are updated to the present index for each staker.