Cycle analytics - implement card ui for stage list

What does this MR do?

Implements the card ui needed for the stages list for cycle analytics.

• Moves the existing stage-nav-item from haml to vue
• Update the style of the list to match the card list in the new designs
• Adds unit tests

Before	After: canEdit = false	After: canEdit = true

CE Port

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31580

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

Related issue

#13076 (closed)

ee/app/controllers/groups/cycle_analytics_controller.rb

@@ -43,10 +43,4 @@ def authorize_group_cycle_analytics!
       render_403
     end
   end
-
-  def is_maintainer?
-     def maintainer?(user)
-    max_member_access(user.id) == Gitlab::Access::MAINTAINER
-  end
-  end
 end