Support to read gzip compressed metadata files

[devendrasr]

The current version of iceberg extension does not support reading iceberg tables that were written with gzip compressed metadata files. Adding one more flag in the commands to consider the metadata files as gz while loading metadata.

scan data:

SELECT * FROM iceberg_scan("s3://my-bucket/icebergwh/someschema/t01", metadata_compression_codec="gzip") limit 10;

scan metadata:

SELECT * FROM iceberg_metadata("s3://my-bucket/icebergwh/someschema/t01", metadata_compression_codec="gzip") limit 10;

scan snapshots:

SELECT * FROM iceberg_snapshots("s3://my-bucket/icebergwh/someschema/t01", metadata_compression_codec="gzip") limit 10;

As of now metadata_compression_codec can be none or gzip; default is none.

[samansmink]

Hey @devendrasr thanks a lot for the PR! In general it looks good.

I added one comment regarding the actual unzipping and I have a more general comment: I would like to see some tests here! Maybe you can add some small test data with a test that confirms this feature works?

[samansmink]

Hey @devendrasr Thanks for the changes, looks good! I have one more comment then I think this is good to go

[devendrasr]

@samansmink Please let me know if you are good to go. Once this is done, we can think about #43

[samansmink]

looks good now, thanks again @devendrasr!