How ckanext-cloudstorage and ckanext-qa could work together?

[KrzysztofMadejski]

Following up on the discussion from https://github.com/ckan/ckanext-archiver/issues/36#issuecomment-286719861: how qa can work on resources stored in the cloud by dataportal provider (so it's part of the infrastructure) without "archiving" them on local application server.

@TkTech: ckanext-cloudstorage can populate the mimetype and hash fields which are core fields on a resource as it's uploaded."

@krzysztofmadejski: Some feaures (like hash and libmagic) would need to be run on the storage server.

[TkTech]

This should be simple, taking a quick look at it. If the resource has the mimetype and hash fields populated simply use those values instead of pulling the file to guess it.