Account shared runner minutes to top-level namespace

Merged Kamil Trzciński requested to merge account-shared-minutes-on-top-level-namespace into master

What does this MR do?

Accounts shared runner minutes and limitations on top-level namespace.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Fixing https://gitlab.com/gitlab-org/gitlab-ee/issues/3564

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/3564

Edited by Kamil Trzciński