Unlock voting power for SD bonded as collateral

Context

This is a proposal to grant voting power for SD bonded by permissionless NOs, following the discussion held in Discord around unlocking SD collateral voting power, and gather more community feedback about it.

At the moment, Node Operators who bond their SD as collateral to run a 4 ETH validator do not have access to the SD voting power, as the SD is locked within a SC (https://etherscan.io/address/0x7Af4730cc8EbAd1a050dcad5c03c33D2793EE91f)

Motivation

In an effort to continue pushing governance decentralization and participation among all SD holders and community members, this is a must have due to:

SD bonded as collateral is already at 970k SD: https://etherscan.io/address/0x7Af4730cc8EbAd1a050dcad5c03c33D2793EE91f

Node Operators are the most committed and engaged users, due to the long term nature of their investment.

Moreover, permissionless NOs are the foundations of ETHx, and the main reason behind its decentralization. Therefore, them having a say in the DAO is mutually beneficial.