delta_kernel crate release considerations

[zachschuermann]

Motivation: I've broken some crates (delta-rs) which take us as a dependency. Want to start logging learnings/processes here.

1. Since we expose arrow in our (default engine) public API, any major version bump from arrow means our crate must major version bump
2. special rules for cargo dependency resolution of 0.x: x is treated as major version basically
3. transitive dependencies are hard. interplay between kernel/delta-rs/datafusion requires coordination (at least for default engine side)

immediate action: splitting crates into kernel/default-engine so kernel core doesn't have arrow dependency. list specific enumeration of arrow versions supported in default-engine (e.g. arrow = 52, 53) and introduce integration testing (actual integration testing not tests/ dir)