Bootstrap Repositories and scoped permissions

Currently the Azure DevOps projects are empty. In order to illustrate securing service connections by securing git repos, we need to:

- [ ] Bootstrap repos using [azuredevops_git_repository](https://registry.terraform.io/providers/microsoft/azuredevops/latest/docs/resources/git_repository) Terraform resource
- [ ] Apply appropriate Admin or Contributor permissions per group
- [ ] Apply branch policy to default branching requiring [minimum reviewers](https://registry.terraform.io/providers/microsoft/azuredevops/latest/docs/resources/branch_policy_min_reviewers). Don't do pipeline run, because then we would have to create a pipeline too…