[feat][misc] PIP-264: Add OpenTelemetry authentication and token metrics

[dragosvictor]

PIP-264

Motivation

Adds authentication and token metrics, as currently described here, to the OpenTelemetry pipeline.

Modifications

• Adds the metrics described in https://github.com/apache/pulsar-site/pull/937 to the collector runs. These metrics are not tied strictly to the broker, and can be used in other places as well (such as the proxy, for instance).
• Added override method org.apache.pulsar.broker.authentication.AuthenticationProvider#initialize(org.apache.pulsar.broker.ServiceConfiguration, io.opentelemetry.api.OpenTelemetry), giving the authentication plugin access to the OpenTelemetry instance.
• Added class org.apache.pulsar.broker.authentication.AuthenticationProviderBase, used to initialize and maintain the AuthenticationMetrics object. This class can be further used by the providers, simplifying development.
• Removed unused static method AuthenticationMetrics.authenticateSuccess

Verifying this change

• [x] Make sure that the change passes the CI checks.

This change added tests and can be verified as follows:

• Added test class org.apache.pulsar.broker.stats.OpenTelemetryAuthenticationStatsTest covering the new metrics

Does this pull request potentially affect one of the following parts:

• [ ] Dependencies (add or upgrade a dependency)
• [ ] The public API
• [ ] The schema
• [ ] The default values of configurations
• [ ] The threading model
• [ ] The binary protocol
• [ ] The REST endpoints
• [ ] The admin CLI options
• [x] The metrics: As described in https://github.com/apache/pulsar-site/pull/937
• [ ] Anything that affects deployment

Documentation

• [ ] doc
• [x] doc-required https://github.com/apache/pulsar-site/pull/937
• [ ] doc-not-needed
• [ ] doc-complete

Matching PR in forked repository

PR in forked repository: https://github.com/dragosvictor/pulsar/pull/22