Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/42939

From https://gitlab.com/gitlab-org/gitlab-ce/issues/36760

Was reverted in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14373

Now that the k8s service is being deprecated in favor of the
Clusters integration, copy all info from the old to the new page.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/41137

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

We need to bump import/export version because we introduced a new
object's hierarchy that is not backwards compatible.

When a project uses fast-forward merging strategy user has
to rebase MRs to target branch before it can be merged.
Now user can do rebase in UI by clicking 'Rebase' button
instead of doing rebase locally.

This feature was already present in EE, this is only backport
of the feature to CE. Couple of changes:
* removed rebase license check
* renamed migration (changed timestamp)

Closes #40301

States this service was deprecated on 10.3 and his behavior depends on
the kubernetes service status. Also includes a link for the release post
for more information.