[feat][broker] PIP-264: Add transaction metrics

[dragosvictor]

PIP-264

Motivation

Adds the transaction metrics as described by https://pulsar.apache.org/docs/next/reference-metrics/#pulsar-transaction to the OpenTelemetry pipeline.

Modifications

• Adds the metrics described in [feat][doc] PIP-264: Add transaction metrics reference apache/pulsar-site#925 to the collector runs.
• Topic transaction buffer statistics are added under the pulsar.broker.topic metric prefix, as they relate closely to the topic metrics. Class PersistentTopicAttributes is updated to reflect this change.

Verifying this change

• Make sure that the change passes the CI checks.

This change updated tests and can be verified as follows:

• Updated test TransactionTest#testTopicTransactionMetrics
• Updated test TopicTransactionBufferTest#testTransactionBufferAppendMarkerWriteFailState
• Updated test PendingAckPersistentTest#testPendingAckMetrics

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 transaction metrics reference apache/pulsar-site#925
• Anything that affects deployment

Documentation

• doc
• doc-required [feat][doc] PIP-264: Add transaction metrics reference apache/pulsar-site#925
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: #37