Implement burst threshold

[bxmmm1]

Instead of cutting off the protocol at 22%:

keep node commission constant (e.g., 5%)
increase protocol fee -> 100%
this drives LST yield to 0%
this decreases demand to stake
there will be no new ETH to spin up nodes
This is a cleaner mechanism than freezing onboarding at a certain % marketshare.

Requirements:
setTotalActiveInPos(uint256 numValidators) is a function that tells the puffer contracts how many validators are currently active. At first this will be only callable by the guardians. In the future, it will be replaced by a ZKP that proves how many active validators are on the beacon chain.

MVP

setTotalActiveInPos(uint256 numValidators) {
  if pufferProtocol.numActive > numValidators:
    $.updateFees(...) 
}