Phase 2 of the Package Registry cleanup policies
### Context
As part of https://gitlab.com/groups/gitlab-org/-/epics/5152, GitLab is adding policies to manage your storage usage with the Package Registry. As an MVC we added the ability to programmatically delete package assets (or files).
### Problem to solve
Thinking beyond the MVC, we will need to add the ability to delete the packages themselves, not just the assets. This will allow users to better manage storage and maintain a tidy workspace.
### Proposal
Follow the [designs](https://www.figma.com/file/L3QzG7TB80tJaBWrlZW6q3/Package-cleanup-policies) to expand the Package Registry cleanup policies MVC to include the packages themselves.
#### Further details
One thing we'd like to avoid is using hardcoded integers for the cleanup policy values. This was brought up by a customer in https://gitlab.com/gitlab-org/gitlab/-/issues/432923 and we'd like to address that when we add new cleanup rules/conditions.
#### Current status
- We've created and validated designs for this work, but we'll need to create additional issues as part of this epic to identify any remaining backend/frontend work.
- The first step will be https://gitlab.com/gitlab-org/gitlab/-/issues/361819 which will create a service for the bulk deletion of packages.
## Owners
* Team: [Package Registry](https://about.gitlab.com/handbook/engineering/development/ops/package/package-registry/)
* Most appropriate slack channel to reach out to: `#g_package-registry`
* Best individual to reach out to: @10io
* PM: @trizzi
* EM: @ckroutil
epic