compress: rework callers to always use the zio_compress calls

This will make future refactoring easier.

There are two we can't change for the moment, because zio_compress_data
does hole detection & collapsing which zio_decompress_data does not
actually know how to handle.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>