Improve testing coverage for SDK

[kohlisid]

Summary

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Currently, we are not testing certain flows such as server start for Async in our UT. Need to add these back to coverage and ensure functionality

1. Check different frameworks Unittest vs pytest etc
2. Check for forked with or without parallelism for performance improvements.
3. Identify more areas for testing -> errors/chaos etc.
4. Have dev tests under flag for an extensive coverage? Maybe can have some e2e style tests

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