draft: added support incremental rebalance in one session

[Sergey-Belyakov]

The idea is to get rid of stop the world during rebalancing without changing the main consumer interfaces. During the response from the heartbeat ErrRebalanceInProgress, the execution of fetch requests continues. In parallel, the reading from the departed partitions is closed.

tests is coming

[prestona]

Hi @Sergey-Belyakov - thanks for opening this PR. I wanted to check if you are aware of #2608, which also proposes changes to the re-balance strategy?

[Sergey-Belyakov]

Hi @Sergey-Belyakov - thanks for opening this PR. I wanted to check if you are aware of #2608, which also proposes changes to the re-balance strategy?

Hi! I have seen this MP, but I wanted to offer an incremental rebalancing option without changing the main interfaces of the consumer

[github-actions]

Thank you for your contribution! However, this pull request has not had any activity in the past 90 days and will be closed in 30 days if no updates occur.
If you believe the changes are still valid then please verify your branch has no conflicts with main and rebase if needed. If you are awaiting a (re-)review then please let us know.