Update Che Helm Chart: Che registries (plugin+devfile) should be part of Che deployment

[skabashnyuk]

Description

Update Che Helm Chart: Che registries (plugin+devfile) should be part of Che deployment
Follow up of #13557

[skabashnyuk]

@sparkoo I would suggest the following plan.

• get familiar with the project https://github.com/che-incubator/chectl and its code structure.
• figure out how to make changes in che Helm chart https://github.com/eclipse/che/tree/master/deploy/kubernetes/helm/che and apply it with chectl
• Add che-plugin-registry pod definition and public route
• Add che-devfile-registry pod definition and public route
• Configure che-plugin-registry and che-devfile-registry url in che master configuration.