Add new TopologyService service

What does this merge request do and why?

This MR is adding Topology Service to the GDK.

This those changes the Topology Service can be installed, and run by GDK.

Related issue: gitlab#469084 (closed)

How to set up and validate locally

1. Checkout the add-support-for-topology-service-in-gdk branch,
2. Stop your GDK gdk stop or gdk kill,
3. Enable the topology service by running gdk config set gitlab_topology_service.enabled true,
4. Execute make Procfile gitlab-topology-service-setup that should install the repository,
5. You can also run make gitlab-topology-service-update as well to ensure that everything works as expected,
6. Start the GDK with gdk start. The new service gitlab-topology-service should now start and the following message should be displayed:

The TopologyService is up and running.

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Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.