feat: ObolValidatorManager

[pinebit]

Summary

In according to the updated design doc:

• introduced deposit() proxy call and changed logic around principal amount withdrawal,
• removed the Clone functionality,
• restricted requestWithdrawal to accept amounts >= principalThreshold,
• restricted requestConsolidation to accept at most 63 source pubkeys,
• adjusted tests to cover the new features.

Details

Please refer to the internal design doc for further details.

How to test it

forge test

ticket: #152

[OisinKyne]

okay looking super good so far.

the thing i asked some questions on was the principalThreshold, i do think we spend some time there, particularly figuring out how we get operators paid. Maybe a time of requestRewardWithdrawal that can only pull less than threshold and has a separate role?

[OisinKyne]

Double approve