WIP: Delete Kubernetes Cluster and Resources

What does this MR do?

This MR addresses the first iteration related to issue #57890 (moved)

The scope here is to expose a way for the user remove the integrated cluster association together while cleaning its

• GitLab Managed Applications
• Cluster roles, role bindings
• Project namespaces

After confirming the modal to remove the integration, user will be redirected to the cluster list and will see a spinner indicating that the removal is ongoing. The cluster detail page wont be accessible anymore for this cluster. Once the cluster is finally deleted, the cluster will disappear from the list.

The second iteration will be done in a next MR which will deal with better presenting feedback to the user such as:

• resource removal status.
• application removal status.
• information could be shown on detail and list page. On detail all the buttons will have to be disabled.

Updates

Some MRs were split and now need to be merged before this one:

• !32793 (closed) (still needs to be moved to gitlab-org/gitlab)
• gitlab!16458 (closed)
• gitlab!16615 (merged)

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry for user-facing changes, or community contribution. Check the link for other scenarios.
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance 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

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