Prometheus Metrics for engine_getBlobsV2 RPC Method

[jevinjojo]

PR description

Prometheus metrics to the engine_getBlobsV2 RPC method to track usage of blob retrieval requests by adding counters and registered the metrics

Fixed Issue(s)

• engine_getBlobsV2 metrics #8927

Thanks for sending a pull request! Have you done the following?

• 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

[jevinjojo]

@Gabriel-Trintinalia Please take a look.