First iteration of Move Kubernetes from service to Cluster page

What does this MR do?

https://gitlab.com/gitlab-org/gitlab-ce/issues/35616#note_43716126: Breaks a bigger deliverable into the first step:

First add the step with the buttons, GKE will link to the form we have, manual creating links to integration

In the first step we will not include the dropdown that allows you to change methods.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/40015.

#35616 (closed)