Auto opening projects in Eclipse Che environment

[vzhukovs]

This changes proposal adds an ability to automatic project open in Eclipse Che environment.

Devfile located by $DEVWORKSPACE_FLATTENED_DEVFILE
Requires installed yq on the runtime image. Doesn't organized to execute on the local image run.

Fixes: eclipse-che/che#21003

Steps to check:
Create the workspace from the following url on the minikube:

https://<your-che-host>/dashboard/#https://github.com/che-incubator/jetbrains-editor-images?che-editor=https://gist.githubusercontent.com/vzhukovs/55caad47363e1b4f3d4a6ab3fe85a03a/raw/23e9ae0d3d50ef914e64fecd56fd63be78f3f1ea/devfile.yaml

• If devfile contains more than one project, then $PROJECTS_ROOT will be opened as project directory.
• If devfile contains only one project, then it will be opened by default.
• if devfile doesn't contain any project, then $PROJECTS_ROOT will be opened as project directory.

Signed-off-by: Vladyslav Zhukovskyi vzhukovs@redhat.com