Forward Validator Balances

[thogard785]

Added a payValidator method so that a validator can transfer their balances from one fastlane auction contract to a new, updated one without having to take custody of the funds.

I also added a check on the 'current' validator to block validators from withdrawing during their own blocks.

[BenSparksCode]

@thogard785 was reviewing this PR and I just noticed all the tests have been removed. Looks like its also like that on main and happened in this commit:
cb7abcc#diff-e5629336bb8c5641c2d1697b526ca73a8aa91bc28a31c5e5c11bc3c2ef580a4e

The last commit in #21 before it was merged into main

Not sure if intentional

[jj1980a]

I don't think we need to block _validator being block.coinbase (we don't block it in payValidatorFee).

To stay consistent with the payValidatorFee function, I suggest adding a _payor param, and corrected values emitted by RelayFeeCollected.

Another suggestion would be dropping the _payor param for both payValidatorFee and paySpecificValidatorFee functions, and set the payor param of the RelayFeeCollected event to msg.sender.

Suggested change

	function paySpecificValidatorFee(address _validator) external payable nonReentrant {
	// TODO: block this when _validator == block.coinbase?
	if (msg.value == 0) revert RelayValueIsZero();
	validatorsBalanceMap[_validator] += msg.value;
	validatorsTotal += msg.value;
	emit RelayFeeCollected(_validator, block.coinbase, msg.value);
	}
	function paySpecificValidatorFee(address _payor, address _validator) external payable nonReentrant {
	if (msg.value == 0) revert RelayValueIsZero();
	validatorsBalanceMap[_validator] += msg.value;
	validatorsTotal += msg.value;
	emit RelayFeeCollected(_payor, _validator, msg.value);
	}