Add support for default values in Iceberg

[malhotrashivam]

Add support for write-default/initial-default on both writing and reading side in Iceberg once apache/iceberg#9502 is released.
Spec: https://iceberg.apache.org/spec/#default-values

[malhotrashivam]

I can see apache-iceberg-1.7.0-rc1 tag in the repo which includes this change, so hopefully not too far in future.

[malhotrashivam]

The change has been released in 1.7.0 :
https://github.com/apache/iceberg/releases/tag/apache-iceberg-1.7.0

[malhotrashivam]

Moved to https://deephaven.atlassian.net/browse/DH-18252