Synced from eclipse/che issue

https://github.com/eclipse/che/issues/21879

Is your enhancement related to a problem? Please describe

VS Code che-code-runtime-description component contributes the container command to the tooling container:

(...)
  - schemaVersion: 2.1.0
    metadata: 
      name: che-incubator/che-code/insiders
    (...)
    components: 
      - name: che-code-runtime-description
        attributes: 
          controller.devfile.io/container-contribution: true 
        container: 
          (...)
          command: 
            - /checode/entrypoint-volume.sh

As a result, the script /checode/entrypoint-volume.sh is executed at workspace startup, but the tooling container entrypoint (for example UDI's) is not.

This is problematic as the tooling container entrypoint may be used to initialise development tools and runtimes.

Describe the solution you'd like

We should use a post-start event rather than the command to start VS Code.

That should be tested though and may require some tweaks to the VS Code startup script (or not).

This is currently VS Code specific but will JetBrains and Theia may be affected too if this feature is implemented in the meantime.