orch-cli rather than oc in upstream

In several places upstream docs has:

An active oc session with administrative permissions to the OpenShift cluster. See Getting started with the OpenShift CLI.

In all procedures that are not OpenShift specific, we should rather have:

An active `{orch-cli}` session with administrative permissions to the {orch-name} cluster.

These are the procedures to fix:

• modules/administration-guide/pages/deploying-che-with-support-for-git-repositories-with-self-signed-certificates.adoc
• modules/administration-guide/pages/using-chectl-to-configure-the-checluster-custom-resource-during-installation.adoc