[fix] [broker] fix subscribe a non-existent cluster/namespace/topic.

[thetumbled]

Motivation

If the topic name is in the format of V1, we can subscribe a topic in non-existent cluster/namespace without any exception.

Modifications

Need to add check for such case.

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

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: thetumbled#51

[thetumbled]

PTAL, thanks. @lhotari @dao-jun @BewareMyPower @poorbarcode

[Technoboy-]

Seems no need try/catch

[thetumbled]

[thomas-bousquet]

Is it possible the same issue is present when the tenant does not exist as well?