Reapply "Add default log publishing concurrency (#1770)" (#1819)

[agarakan]

Description of the issue

Re-enables concurrency by default for log publishing to cloudwatch

Description of changes

Reverts #1819
This is reintroduced after introducing a retryHeap and circuitbreaker mechanism to alleviate the potential scenario where poison pill bug causes saturation of Senderpool workers.

License

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Tests

Unit tests pass

make lint
make fmt
make fmt-sh
make test

Requirements

Before commiting your code, please do the following steps.

1. Run make fmt and make fmt-sh
2. Run make lint

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Integration Tests

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