feat(KeyRegistry): add settable IdRegistry

[horsefacts]

Motivation

The KeyRegistry contract owner should be able to update the IdRegistry address, in case of a future upgrade.

Change Summary

Use a minimal interface for IdRegistry in KeyRegistry. Add an authenticated setter function.

Merge Checklist

Choose all relevant options below by adding an x now or at any time before submitting for review

• The PR title adheres to the conventional commits standard
• The PR has been tagged with change type label(s) (i.e. documentation, feature, bugfix, or chore)
• The PR's changes adhere to all the requirements in the contribution guidelines
• This PR does not require changes to the Farcaster protocol

Additional Context

Close #264

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PR-Codex overview

Detailed summary

• The gas usage for two functions in the BundleRegistryGasUsageTest contract has increased.
• The gas usage for two functions in the IdRegistryGasUsageTest contract remains the same.
• An event SetIdRegistry has been added to the KeyRegistry contract.
• Two new functions testFuzzOnlyAdminCanSetIdRegistry and testFuzzSetIdRegistry have been added to the KeyRegistryTest contract.
• The KeyRegistry contract now uses the IdRegistryLike interface instead of the IdRegistry contract.

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[github-actions]

Coverage after merging horsefacts/update-id-registry-in-key-registry into main will be

98.70%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src
Bundler.sol	100%	100%	100%	100%
FnameResolver.sol	100%	100%	100%	100%
IdRegistry.sol	100%	100%	100%	100%
KeyRegistry.sol	100%	100%	100%	100%
StorageRent.sol	100%	100%	100%	100%
src/lib
Signatures.sol	100%	100%	100%	100%
TransferHelper.sol	0%	0%	0%	0%	15, 15, 15, 25–26, 26, 26
TrustedCaller.sol	100%	100%	100%	100%