Rename Pulsar txn metrics to specify OpenMetrics

[hezhangjian]

Motivation

See https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md
A COUNTER needs metrics_name_total or metrics_name_created

This PR contains metric name broken changes.

Modifications

Rename counter's _count to _total

metrics name broken changes

• rename pulsar_txn_committed_count to pulsar_txn_committed_total
• rename pulsar_txn_aborted_count to pulsar_txn_aborted_total
• rename pulsar_txn_created_count to pulsar_txn_created_total
• rename pulsar_txn_timeout_count to pulsar_txn_timeout_total
• rename pulsar_txn_append_log_count to pulsar_txn_append_log_total

Documentation

• doc
  As mentioned above, the metrics name has changed

[github-actions]

@Shoothzj Please provide a correct documentation label for your PR.
Instructions see Pulsar Documentation Label Guide.

[nicoloboschi]

This is a breaking change. If we really want to go with this path we should keep both the versions, deprecate the older ones and eventually remove them in a future version

[michaeljmarshall]

LGTM.

@nicoloboschi - you are correct that this is a breaking change. @Shoothzj proposed this change on the mailing list: https://lists.apache.org/thread/ojwn2l2rtp4lyyrjbhmnf0m6cprjfwx8. The thread mentions that upgrading the prometheus client depends up fixing counters that do not end with _total. We have already merged #13785. I don't think we can easily make it work to expose both metrics, so as long as we communicate to our users, I think this is okay.

[nicoloboschi]

Thanks @michaeljmarshall for pointing the ML discussion.
I agree that sooner or later we have to move to newer versions of Prometheus and it's better to rename all the needed metrics in the same release

[hezhangjian]

@nicoloboschi I will follow up on this. Ensure all the metrics to be renamed before 2.11.0

[hezhangjian]

/pulsarbot run-failure-checks