Adds cert-manager 1.4 to the project template

What is this about

Introduces cert-manager 1.4 to the cluster management project template.

Relates to

gitlab-org/gitlab#212589 (closed)

Manual QA

I've copied branch into another project and configured it as the cluster management project.

Pipeline that installs ingress and CM succeeds: https://gitlab.com/Alexand/cluster-management-cm-1-4-cp/-/jobs/1526197834

SSL properly provisioned: