New rake task to import the groups for evaluation process

What does this MR do and why?

This merge request adds a new feature to the GitLab application, which allows users to easily set up an evaluation environment for testing AI-powered features. It includes the ability to create subgroups, subprojects, and import sample data, all with a simplified user interface. Additionally, it provides instructions on how to set up the environment and how to use the evaluation framework. This feature will be useful for developers and researchers who want to test and evaluate AI-powered features in GitLab.

This feature is available on dev environment only.

The goal here was to automate points 1-8 from this documentation to avoid space for human error.

MR acceptance checklist

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Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.