Support IsolationLevels and Concurrency Safety Validation Checks

[sungwy]

Feature Request / Improvement

Support enforcing Isolation Levels from specified snapshot ID

https://iceberg.apache.org/docs/latest/spark-configuration/#write-options

There's been a lot of continued interest in using multiple PyIceberg applications concurrently and having proper support for optimistic concurrency.

I think the best place to start is through the implementation of the individual validation functions

Once this is complete, we'll be able to introduce the Isolation Levels and correctly implement the validation logic in the _OverwriteFiles snapshot producer, similarly to the Java implementation

[jqin61]

Hi I am interested in working on it!

[sungwy]

Some relevant links to the Java implementation

• validateNewDataFiles flag -> MergingSnapshotProducer: validateAddedDataFiles
• validateNewDeletes flag -> MergingSnapshotProducer: validateDeletedDataFiles