MevEthShareVault and WagyuStaker should inherit Auth and have fund recover functions

[sandybradley]

Issue

MevEthShareVault and WagyuStaker can be used as vaildator withdraw addresses. They should inherit Auth for the following reasons:

• payValidatorWithdraw requires care when calling as it should correspond to a single validator amount. This should be an operatorOnly function.
• mevEth address should be upgradeable
• recover funds / tokens functions should be added

[0xKitsune]

I created a new branch to add this functionality. Can you give an idea of what the recoverFunds() function should look like? Are you envisioning that this function would take a receiver address and simply send all funds to that address?

[sandybradley]

I had in mind something like ...

    function revoverFunds(address recipient, uint256 amount) external onlyAdmin {
        SafeTransferLib.safeTransferETH(recipient, amount);
    }

    function revoverToken(address token, address recipient, uint256 amount) external onlyAdmin {
        ERC20(token).safeTransfer(recipient, amount);
    }

[0xKitsune]

Sounds good, I will add this as well as some tests and PR today.