feat: add Proposal Validator

[0xChin]

Closes OPT-757, OPT-758

[0xOneTony]

Left a few comments, there is a confusion around proposalId of ProposalValidator and OptimismGovernor also for proposalType.
We should define as ProposalType the actuall proposal type, e.g. governance funds proposal, protocol or governance upgrade proposal etc.. (this is a new thing nothing to do with the proposalType that already exist on the governor).
Then ProposalVotingType should be the existing proposalType that is reffering to the ProposalTypeConfigurator. I know it is kinda confusing cause we cant edit the code on the governor side for now but still we should differentiate these 2 on our contracts

[0xOneTony]

Some comments! nice job 🔥

[linear]

OPT-758 Define structure of the `Top100DelegateProposalValidator` contract

OPT-757 Define the `Top100DelegateProposalValidator` interface

[0xOneTony]

Some small details but overall great job! 🔥 Didnt check the tests yet will do when we have the fixes

[0xOneTony]

maybe we could change the name of the error to be more accurate?

[0xChin]

I've tried lol chore: improve errors naming

[0xOneTony]

I was thinking more something like ProposalValidator_AlreadyMovedToVote since AlreadyProposed can be confused with the submit proposal

[0xChin]

I like saying that it is inVoting given that we use that naming for the proposals that have been moved to vote:

optimism/packages/contracts-bedrock/src/governance/ProposalValidator.sol

Lines 41 to 61 in 30c171b

	/// @notice Data structure for storing proposal information.
	/// @param proposer The address that submitted the proposal.
	/// @param targets Target addresses for proposal calls.
	/// @param values ETH values for proposal calls.
	/// @param calldatas Function data for proposal calls.
	/// @param description Description of the proposal.
	/// @param proposalType Type of the proposal from the ProposalType enum.
	/// @param inVoting Whether the proposal has been moved to the voting phase.
	/// @param delegateApprovals Mapping of delegate addresses to their approval status.
	/// @param remainingApprovalsRequired Number of approvals still needed before voting.
	struct ProposalData {
	address proposer;
	address[] targets;
	uint256[] values;
	bytes[] calldatas;
	string description;
	ProposalType proposalType;
	bool inVoting;
	mapping(address => bool) delegateApprovals;
	uint256 remainingApprovalsRequired;
	}

[0xOneTony]

i think this name and description is not that accurate, maybe _validateAttestation is better, wdyt?

[0xChin]

The idea is to make all validation there in the future, that's the reason why targets, values, and calldatas are provided but not used yet

[0xOneTony]

🚀