Delegate override vote

[Amxx]

Replaces #5160 (was not able to push commit to arr00's repository.

To discuss

• Contract naming
  • VotesOverridable: this is an extension of Votes that provides more features. It can be used to implement overrides, but it may also be used for other stuff. Maybe the name should not be so tightly associated with override.
  • GovernorOverrideDelegateVote: this is a counting module. IMO the name should reflect that.
    • GovernorCountingOverridable ?
• Errors naming
  • GovernorAlreadyCastVoteOverride: I think we can do better.
• Function naming
  • overrideVote, overrideVoteBySig: should it include "cast"
• Events
  • events to emit when overrideVotes is executed.
  • Is it possible to differentiate between a normal vote and an override vote in the VoteCast event?
• Extension Compatibility
  • The PreventLateQuorum extension expects that all votes call the internal _castVote function. We need to ensure these two extensions are compatible. Some options:
    1. Call _castVote from this function. This would necessitate the usage of vote params.
    2. Create a new internal function that is called every time the vote tally is updated--similar to the idea of the _update function on the ERC20 token.

PR Checklist

• Tests
• Documentation
• Changeset entry (run npx changeset add)

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🦋 Changeset detected

Latest commit: ca6feb3

The changes in this PR will be included in the next version bump.

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openzeppelin-solidity	Patch

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