Allow an admin to specify Che default editor and containers

Synced from eclipse/che issue

https://github.com/eclipse/che/issues/21353

Is your enhancement related to a problem? Please describe

If no devfile is present in a git repository the default is to start a workspace with only one component (the Theia container) and Theia as the editor.

That's a bad UX as the Theia container misses many langue tools and because an admin cannot change this behavior.

Describe the solution you'd like

The default container should be a UDI container. Both the default container and the default editor should be configurable in the CheCluster CR.

(...)
workspaces: 
  (...)
  defaultComponent or defaultContainer ?: |
    name: universal-developer-image
    container: 
        image: quay.io/devfile/universal-developer-image:ubi8-latest
        memoryRequest: 256M
        memoryLimit: 1536M
        cpuRequest: 0.1
        cpuLimit: 0.5
  defaultEditor: eclipse/che-theia/next
(...)

Additional Context

This is a #21340 subtask.

Release Notes Text

Che administrators can now configure the default editor (Theia, VS Code, IntelliJ or PyCharm) and the default container. Those defaults are used when the developer doesn't specify an editor or doesn't specify a devfile. The configuration can be done in the CheCluster Custom Resource in the the workspaces section using the just introduced defaultComponent and defaultEditor fields.