Specify Filetype

[matthias-Q]

Hi,
I noticed that some widely used tool product parquet files with no ending (e.g. trino/athena when using UNLOAD) Would be nice if this cool could accept a parameter that specifies the filetype instead of guessing it from the ending.

[matthias-Q]

I am preparing a PR for this issue using https://github.com/mmalecot/file-format. This should allow us to detect the filetype of at least Avro and Parquet files.