Fixes #31257 - support incremental update for debs

[m-bucher]

What are the changes introduced in this pull request?

Support copying of deb-packages in incremental Update of ContentViews .

Considerations taken when implementing this change?

Adding deb-packages does not support dependency-solving. Trying to do that will fail the incremental update.
#10734 ensures the dependency-solving option is ignored for deb-packages/-repositories.

What are the testing steps for this pull request?

No UI support; use the Content_view_versions / incremental_update REST-API endpoint for testing:

POST /katello/api/content_view_versions/incremental_update
...
{
  "add_content": {
    "deb_ids": [ <pkg_ids> ]
  }
}