feat: introduce io engine

[MrCroxx]

What's changed and what's your intention?

Please explain IN DETAIL what the changes are in this PR and why they are needed. :D

WIP...

Checklist

• I have written the necessary rustdoc comments
• I have added the necessary unit tests and integration tests
• I have passed make all (or make fast instead if the old tests are not modified) in my local environment.

Related issues or PRs (optional)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
foyer-storage/src/device/direct_file.rs	85.08% <ø> (ø)
foyer-storage/src/device/direct_fs.rs	87.42% <ø> (ø)
foyer-storage/src/device/mod.rs	78.57% <ø> (ø)
foyer-storage/src/device/monitor.rs	80.90% <ø> (ø)
foyer-storage/src/io/allocator.rs	88.46% <ø> (ø)
foyer-storage/src/io/bytes.rs	51.06% <ø> (ø)
foyer-storage/src/io_buffer_pool.rs	85.71% <ø> (ø)
foyer-storage/src/large/batch.rs	85.29% <ø> (ø)
foyer-storage/src/large/reclaimer.rs	85.36% <ø> (ø)
foyer-storage/src/large/scanner.rs	76.00% <ø> (ø)
... and 7 more