Redshift COPY Support

Redshift Copy SQL has multiple parameters that are not supported (for example Authorization parameter IAM_ROLE)

https://docs.aws.amazon.com/redshift/latest/dg/r_COPY-alphabetical-parm-list.html

```
COPY schema.table
FROM 's3://bucket-example/folder/file.csv'
IAM_ROLE 'arn:aws:iam::123456789012:role/my_iam_role'
DELIMTER ','
FORMAT AS CSV
GZIP
```

Start by locating the Rust SQL parser entry point for COPY statements and compare its supported parameters with the AWS Redshift COPY parameter list linked in the issue. Add coverage for IAM_ROLE and the other requested parameters shown by that comparison, then verify that the example statement parses successfully.

Written by the indexing model from the issue text.