Add OpenTelemetry Proto Metrics Reader Extension

[suraj-goel]

Fixes #17644.

Description

• Added OpenTelemetry Proto Metrics Reader extension.
• Benchmark results

Release note

• A new extension, druid-opentelemetry-extensions, has been added to enable ingestion of metrics in OpenTelemetry Protocol (OTLP) format.
• This extension allows Druid to ingest metrics data directly from OpenTelemetry sources using the OTLP format, aligning Druid with industry-standard telemetry protocols.
• To use this extension, refer to attached README

This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.