Add unit tests for Parquet methods used by Apache Iceberg

[andygrove]

What is the problem the feature request solves?

PR #1920 adds/updates methods intenced to be used by Apache Iceberg, but did not add any tests. This is a follow-on issue to add tests so that we can avoid regressions in the behavior that Apache Iceberg expects.

Describe the potential solution

No response

Additional context

No response

[andygrove]

Now that we run Iceberg integration tests as part of Comet CI, this issue is no longer needed