Distinguish between Docker images and Helm charts in the Container Registry
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### Problem to solve
**Note:** Until recently, this issue was blocked by the rollout of the new Container Registry version. This work has been completed for GitLab.com (https://gitlab.com/groups/gitlab-org/-/epics/5523) and is in progress for self-managed instances (https://gitlab.com/groups/gitlab-org/-/epics/5521).
Helm 3 is the eagerly awaited next release of Helm, the Kubernetes package manager and deploy tool. With the launch of Helm 3, [which is now in beta](https://helm.sh/blog/helm-v3-beta/), pushing and pulling charts can now be done via OCI Registry. This means that users can now utilize the GitLab Container Registry for hosting Helm charts.
However, just because we are using the Container Registry as storage, does not mean that we should display Helm charts alongside Docker repositories, images and tags alongside them. We will need to either add a new page to the `Packages` menu item, or give users a way to distinguish between an image and chart.
### Intended users
* [Delaney (Development Team Lead)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#delaney-development-team-lead)
* [Sasha (Software Developer)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sasha-software-developer)
* [Devon (DevOps Engineer)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#devon-devops-engineer)
* [Sidney (Systems Administrator)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sidney-systems-administrator)
### Further details
<!-- Include use cases, benefits, and/or goals (contributes to our vision?) -->
### Proposal
- Give users the ability to view their Helm charts that are hosted in the GitLab Container Registry, by introducing a new page under the Package menu, called `Helm Charts`. The page should include the chart name, version, last updated date, and size.
#### User interface



### Permissions and Security
The permissions should follow the same levels as Docker.
#### Project Permissions: UI
| Action | Guest | Reporter | Developer | Maintainer | Owner |
|--------|-------|----------|-----------|------------|-------|
| Pull from Container Registry / Helm Chart | | x | x | x | x |
| Publish to Container Registry / Helm Chart | | | x | x | x |
### Documentation
- Will need to add new documentation for Helm Charts
### Testing
<!-- What risks does this change pose? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing? See the test engineering process for further help: https://about.gitlab.com/handbook/engineering/quality/test-engineering/ -->
### What does success look like, and how can we measure that?
- Measure number of charts deleted
- Measure number of deletions accepted
- Measure number of deletes cancelled
issue