Partition Spec Evolution API

[c-thiel]

The general philosophy of any engine that implements Iceberg-Rust is that they should not care about things like field-IDs. Therefore we try to hide this logic behind APIs. To allow evolution of the partition spec, we have the UpdateSpec API in Python and the BaseUpdatePartitionSpec (implements UpdatePartitionSpec) in Java.

Mutating partition specs works differently in V1 and V2 of the spec. I think it would be OK to focus on V2 first and simply fail to write V1 for now. @liurenjie1024, @Xuanwo do you agree or is mutation / write for V1 important?

This should add the update_spec method to Transaction.

[ZhiHanZ]

Can I take a trial on this issue?

[c-thiel]

Sure @ZhiHanZ! Let us know if there are any challenges or questions!

[liurenjie1024]

Thanks for @c-thiel for raising this. I agree that we should focus on v2 first, and add v1 support later.