WIP: Kubernetes connect based on project

What does this MR do?

Ability to pass in a project to Clusters::Platform::Kubernetes which you can then use to connect / operate the kubernetes cluster.

There will be multiple projects which will use Clusters::Platform::Kubernetes with group level clusters so #first_project aka Clusters::Cluster#project won't cut it anymore.

• Some connections don't need to know project
• Some connections do need to know project so that it can work out the namespace (Related: https://gitlab.com/gitlab-org/gitlab-ce/issues/53592)

What are the relevant issue numbers?

#34758 (closed), https://gitlab.com/gitlab-org/gitlab-ce/issues/53592

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides