Fixes #38009 - content-override with deselect

[m-bucher]

For host repository-sets with structured apt enabled setting content-overrides using bulk-action:
de-selecting deb-repos after using select-all has no effect.

What are the changes introduced in this pull request?

find_content_overrides() helper method must be adapted to work with one content for each katello-repo (#11058).

Considerations taken when implementing this change?

What are the testing steps for this pull request?

1. Enable structured apt and have multiple structured deb-content
2. Create Host attached to deb-content
3. Try to reset content-overrides for that host in the following way:
4. Select all content
5. De-select part of the deb-repos
6. Use bulk-action to override content state

ToDo

• test Show all selected
• write more unit tests 🙈

[chris1984]

@m-bucher can you elaborate more on step 1? How do I enable structured apt and do you have a url that has structured apt content to sync from?

[m-bucher]

@m-bucher can you elaborate more on step 1? How do I enable structured apt and do you have a url that has structured apt content to sync from?

@chris1984
Structured APT can be enabled by setting deb_enable_structured_apt to true.
After that new deb/apt (Root-)Repositories will use structured publishing. If you have pre-existing deb/apt repositories and want to convert them you have to use the katello:migrate_structure_content_for_deb rake task.

All deb/apt repositories you find on the internet are structured*. As in they define custom release/distribution names (e.g. stable, bookworm, noble) and components (e.g. main, non-free, universe).
Before structured-apt, Katello and Pulp always created release default with component all and just put all synched packages into that.
Now it mirrors the structure of the upstream repository (there should no longer be a dists/default folder in the repository published by Pulp/Katello).

* there are some weird flavours of APT-Repos out there, but the OS-repos of the distributions (Debian, Ubuntu, etc) are structured