Snapshot Changes should have a Streaming Interface

[RussellSpitzer]

Feature Request / Improvement

Currently SnapshotChanges only provides a caching interface that eagerly materializes all file changes into in-memory lists and returns Iterable. There are use cases where returning a streaming CloseableIterable would be preferable see #13556 for example.

I think we probably should just add CloseableIterable interfaces to SnapshotChanges as well and just have the caching calls wrap them.

Query engine

None

Willingness to contribute

• I can contribute this improvement/feature independently
• I would be willing to contribute this improvement/feature with guidance from the Iceberg community
• I cannot contribute this improvement/feature at this time