Review / cleanup package related code around Restrict and Delete

In #7081, we managed to simplify some of the rendering related to package files. Namely:

1. Allow restrict of package files (unless public install) - previously for non public installs, there was a check related to package files / s3 storage, but we decided it was no longer needed
2. Allow delete of package files (after publish) - previously delete was only allowed for unpublished files

We need to review other areas of the code to make sure this simplified logic is consistent (e.g. editfiles fragment and/or APIs)

Note: We checked in with @pameyer for whom this logic was originally intended and he was fine with the change (in his case the sbgrid installation is a public install, and he curates all datasets, so can reject draft versions that attempt to delete files from versions when they should not.

Start by reading the changes in #7081, then inspect the editfiles fragment and the related APIs for restrict and delete handling. Compare their package-file and S3-storage logic with the simplified behavior described here. Done means the relevant paths consistently allow restriction and post-publish deletion where intended.