[feat][broker] PIP-264: Add OpenTelemetry managed cursor metrics

[dragosvictor]

PIP-264

Motivation

Adds Managed Cursor metrics, as currently described here, to the OpenTelemetry pipeline.

Modifications

• Adds the metrics described in [feat][doc] PIP-264: Add OpenTelemetry managed cursor metrics reference pulsar-site#929 to the collector runs.

Verifying this change

• Make sure that the change passes the CI checks.

This change modified tests and can be verified as follows:

• Updated tests ManagedCursorMetricsTest#testManagedCursorMetrics and ManagedCursorMetricsTest#testCursorReadWriteMetrics to cover the OpenTelemetry 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
• The metrics: As described in [feat][doc] PIP-264: Add OpenTelemetry managed cursor metrics reference pulsar-site#929
• Anything that affects deployment

Documentation

• doc
• doc-required [feat][doc] PIP-264: Add OpenTelemetry managed cursor metrics reference pulsar-site#929
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: dragosvictor#34