Avd2.2.0 cvp3.0.0 debian

[ankudinov]

A proposal for the new AVD container setup.
Most important changes:

• AVD and CVP collections are now part of the container. It's still possible to override that with the custom version by using bind mount.
• No env variable to install custom requirements or ansible. If required, override by using custom Dockerfile or devcontainer.json
• CMD is replaced with ENTRYPOINT to work consistently between different use cases: devcontainer/cli
• entrypoint script is simplified and enhanced to detect various use cases and react accordingly
• gitconfig is only processed by entrypoint script if container is called directly. In case of devcontainer, native vscode workflow will be used
• minor enhancement to the Dockerfile format
• optimised use of user accounts