feat: implement effective delegation shares

[atheeshp]

Description

This proposal for the Cosmos SDK suggests modifying the staking rewards distribution to account for liquidity risk by differentiating between locked (vesting) and unlocked tokens. The proposed "VestingRewardMultiplier" (VRM) parameter adjusts rewards for locked tokens, allowing stakers who contribute more liquid (unlocked) tokens to earn higher rewards. By setting VRM between 0 and 1 (used 0.3 in this POC), Cosmos can gradually shift reward distribution, potentially incentivizing more liquid staking and aligning network incentives. Considerations include user fairness, computational efficiency, and a smooth migration path for current delegations.

ref: Proposal: Adjusted Staking Rewards Distribution in Cosmos SDK #22001

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