refactor(meta): optimize Hummock version delta deletion

[zwang28]

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What's changed and what's your intention?

This PR removes the unnecessary clone during delete_version_deltas. The clone may has significant impact on the performance if the number of hummock_version_deltas is large. In the worst case, deleting hummock_version_deltas can be slower than adding new ones, leading to a backlog of hummock_version_deltas.

This PR also add logs to help monitor the progresss of Hummock version redo during startup. It's helpful for troubleshooting when there're lots of
hummock_version_deltas and the redo is slow.

This PR also move time travel metadata GC to dedicated tokio task.

Checklist

• I have written necessary rustdoc comments.
• I have added necessary unit tests and integration tests.
• I have added test labels as necessary.
• I have added fuzzing tests or opened an issue to track them.
• My PR contains breaking changes.
• My PR changes performance-critical code, so I will run (micro) benchmarks and present the results.
• My PR contains critical fixes that are necessary to be merged into the latest release.

Documentation

• My PR needs documentation updates.

Release note