Improve performance of LayeredKeyValueStorage.get method

[ahamlat]

PR description

When profiling big blocks on a devnet where besu is sync'ing with lock step, I noticed in the profiling that using Bytes.toHexString for comparaison is hurting the performances because of the usage of megamorphic calls in this method, like get method on Bytes implementations. The pink part of the profiling below corresponds to the cost of the get megamorphic call

This PR changes the way keys are compared by working on the underlying arrays and use Arrays.compare to do the comparaison. We can see below the new profiling following this optimization.

Fixed Issue(s)

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• Checked out our contribution guidelines?
• Considered documentation and added the doc-change-required label to this PR if updates are required.
• Considered the changelog and included an update if required.
• For database changes (e.g. KeyValueSegmentIdentifier) considered compatibility and performed forwards and backwards compatibility tests

Locally, you can run these tests to catch failures early:

• spotless: ./gradlew spotlessApply
• unit tests: ./gradlew build
• acceptance tests: ./gradlew acceptanceTest
• integration tests: ./gradlew integrationTest
• reference tests: ./gradlew ethereum:referenceTests:referenceTests

[garyschulte]

Great fix. I never really liked the string comparison, but wasn't aware of the performance implications.