feat: Implement kube config injection on openshift cluster

[mmorhun]

Signed-off-by: Mykola Morhun mmorhun@redhat.com

What does this PR do?

Implements injection of Kubernetes config from host into Che workspace for Openshift infrastructure.
Also implements config injection for Openshift cluster with kubectl (yes, kubectl and oc is not interchangeable in all cases).

How to test

Start your cluster, deploy Che on it. When ready run the following command:

chectl workspace:inject -k -c <container-name>

If one wants to test specific CLI tool (oc or kubectl) with the cluster, then one need to remove other options from CLI list in getClusterClientCommand function in src/util.ts file.

To be able to test in some local clusters which has 'bad' TLS certificate, one need to relogin with --insecure-skip-tls-verify option and run chectl (as described above) before autologout. For example, for CRC, the command might look like:

oc logout --insecure-skip-tls-verify && oc login -u kubeadmin -p BdTY8-Vra64-gD3cI-dAPS6 https://api.crc.testing:6443 --insecure-skip-tls-verify && ./run workspace:inject -k -c nodejs

What issues does this PR fix or reference?

eclipse-che/che#15987

[azatsarynnyy]

I've checked it with Che running on minishift disabling kubectl in getClusterClientCommand.
So, workspace:inject -k successfully copied my kubeconfig into a sidecar with oc. 👍