[feat] Use producer name and sequence number as fallback key in Key_Shared implementation

[pdolif]

Fixes #23212

Motivation

Taken from issue:

The Key_Shared implementation expects that the incoming message contain either a key/keyBytes or orderingKey.
If the key isn't set, the implementation will use the bytes of the NONE_KEY string as the key. This could be a surprise to users since the implications of not setting the key is not documented.

The problem that this causes is that all messages without a key will handled by a single consumer. If any of these messages is in redelivery, it will cause all message delivery to be blocked.

Modifications

• Updated all parts where NONE_KEY was used as a default: Prefer 1) ordering key, 2) partition key, 3) new fallback key derived from producer name and sequence number, 4) NONE_KEY

Verifying this change

• Make sure that the change passes the CI checks.

This change added tests and can be verified as follows:

• Updated KeySharedSubscriptionTest to verify that messages are distributed evenly among consumers and based on the producer-derived key if no ordering/partition key is given
• Added test case to CommandsTest for the new fallback key
• Updated PerformanceProducerTest to reflect distribution of messages to multiple consumers if key is not set

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

If the box was checked, please highlight the changes

• 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
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: pdolif#2

[github-actions]

@phil-cd Please add the following content to your PR description and select a checkbox:

- [ ] `doc` <!-- Your PR contains doc changes -->
- [ ] `doc-required` <!-- Your PR changes impact docs and you will update later -->
- [ ] `doc-not-needed` <!-- Your PR changes do not impact docs -->
- [ ] `doc-complete` <!-- Docs have been already added -->

[lhotari]

Mailing list discussion: https://lists.apache.org/thread/fyk0z2fsvv1fqp5dpdlzhqb7cd9qjr4j

[lhotari]

LGTM. Great work @phil-cd ! Thanks for contributing.

[pdolif]

/pulsarbot rerun-failure-checks