feat(meta): make complete barrier non-async in worker loop

[wenym1]

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What's changed and what's your intention?

Previously after we collect a barrier, we call complete_barrier to commit the a new hummock snapshot and also do some post-collection work to update the catalog metadata. The complete_barrier is an async method, which involves works like doing IO to meta store backend, and acquiring async lock. The complete_barrier call will in-place block the global barrier manager worker loop, which may block the handling of other events.

In this PR, we change to spawn a task a do the complete_barrier work, so that the call on it will be non-blocking. We also refactor the method to split it into two parts, one called update_snapshot, which updates the hummock snapshot, and the other called update_tracking_jobs, which updates the information of tracked create streaming jobs.

Checklist

• [ ] I have written necessary rustdoc comments
• [ ] I have added necessary unit tests and integration tests
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Documentation

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Release note

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