Feature request: Gitlab Harbor group integrations

There are project-level integrations, but no group-level integrations. For example harbor project is commonly integrated on group level by creating one Harbor project for a whole Gitlab group.

This is currently not possible with this provider, even though it would be really useful feature and shouldn't even be that hard, because it's already implemented at project level: https://registry.terraform.io/providers/gitlabhq/gitlab/latest/docs/resources/project_integration_harbor

Implementation Guide

• Read the CONTRIBUTING.md guide for setting up your local development environment and clone the community fork of this project.
• Follow the CreatingANewResource.md guide and create a new resource in internal/provider called gitlab_group_integration_harbor.