Create Snyk Organizations with top level GitLab groups[🙏]

[Robthreefold]

Describe the user need
With the orgs:data creation with GitLab, it will create a Snyk organization for the groups and their subgroups. The customer would like a flag that you can specify a flag that will tell orgs:data to create Snyk organizations with subgroups or without subgroups.

Describe expected behavior

The plan would be a flag like include_subgroups for GitLab only. When this flag is false it will remove sub-groups from the groups collected when orgs:data is run. Snyk-api-import will only create orgs for the top-level groups.

Additional context

I believe this would need to be specified in this file on line 23 and having an if block when a flag is specified too, exclude sub-groups with top_level_only flag in this doc.