[improve] [client] support aggregate metrics for partition topic stats

[rdhabalia]

Motivation

Right now, Producer client stats returns incorrect rate values for partition topic instead giving aggregate value across all partitions. Right now it always returns 0 but it can be aggregated for partition topic and give to client.

Modifications

Update aggregate rate value for producer stats.

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

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This change added tests and can be verified as follows:

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• 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
• Anything that affects deployment

Documentation

• doc
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• doc-complete

Matching PR in forked repository

PR in forked repository:

[codecov-commenter]

Codecov Report

Merging #18214 (371a754) into master (6c65ca0) will increase coverage by 15.86%.
The diff coverage is 33.19%.

@@              Coverage Diff              @@
##             master   #18214       +/-   ##
=============================================
+ Coverage     34.91%   50.78%   +15.86%     
- Complexity     5707     8723     +3016     
=============================================
  Files           607      612        +5     
  Lines         53396    53579      +183     
  Branches       5712     5742       +30     
=============================================
+ Hits          18644    27208     +8564     
+ Misses        32119    23367     -8752     
- Partials       2633     3004      +371     

Flag	Coverage Δ
unittests	50.78% <33.19%> (+15.86%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
.../main/java/org/apache/pulsar/PulsarStandalone.java	0.00% <0.00%> (ø)
.../apache/pulsar/broker/admin/impl/ClustersBase.java	76.66% <0.00%> (+67.62%)	⬆️
...pache/pulsar/broker/admin/impl/NamespacesBase.java	63.32% <ø> (+48.79%)	⬆️
.../pulsar/broker/service/AbstractBaseDispatcher.java	52.14% <0.00%> (+6.28%)	⬆️
...che/pulsar/broker/service/BacklogQuotaManager.java	12.39% <0.00%> (+2.91%)	⬆️
.../pulsar/broker/service/BrokerServiceException.java	41.66% <0.00%> (+16.66%)	⬆️
...ava/org/apache/pulsar/broker/service/Consumer.java	68.08% <0.00%> (+6.07%)	⬆️
...ava/org/apache/pulsar/broker/service/Producer.java	62.13% <0.00%> (+2.49%)	⬆️
...pulsar/broker/service/PulsarCommandSenderImpl.java	66.66% <0.00%> (ø)
...va/org/apache/pulsar/broker/service/ServerCnx.java	45.85% <0.00%> (+0.51%)	⬆️
... and 219 more