* This PR/commit comprises of the following:
- Support to fallback on the older systemVM template in case of no change in template across ACS versions
- Update core user to cloud in CKS
- Display details of accessing CKS nodes in the UI - K8s Access tab
- Update systemvm template from debian 11 to debian 11.2
- Update letsencrypt cert
- Remove docker dependency as from ACS 4.16 onward k8s has deprecated support for docker - use containerd as container runtime
* support for private registry - containerd
* Enable updating template type (only) for system owned templates via UI
* edit indents
* Address comments and move cmd from patch file to cloud-init runcmd
* temporary change
* update k8s test to use k8s version 1.21.5 (instead of 1.21.3 - due to https://github.com/kubernetes/kubernetes/pull/104530)
* support for private registry - containerd
* Enable updating template type (only) for system owned templates via UI
* smooth upgrade of cks clusters
* update pom file with temp download.cloudstack.org testing links
* fix pom
* add cgroup config for containerd
* add systemd config for kubelet
* add additional info during image registry config
* update to official links
