Add GraphQL API to delete container repository tags

🌲 Context

In !47175 (merged), we added a mutation to destroy a container repository.

This MR adds the other mutation: the API to delete container repository tags.

The container repository tags don't live in the ruby backend. They are in the container registry. Therefore each tag deletion will trigger network requests to the Container Registry. As such, we're going to limit the number of tags that a single call API can delete.

This API will be used by the UI in #276900 (closed).

This MR is the result of the Package team 🍐 programming session with @hswimelar. @sabrams and @nmezzopera

What does this MR do?

• Add the Mutations::ContainerRepositories::DestroyTags mutation
• Add the relevant specs (mutation and request)

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team