Provide a way for admins to approve/disapprove runner registration

Problem to solve

Given that a GitLab user has the ability to spin up runners easily locally, docker containers, remote servers, it is possible that the number of runners can grow exponentially (in this case, these are being spun up on AWS thus raising cost concerns). Given InfoSec restrictions, going with the autoscaling runners is not an option.

Intended users

DevOps Engineer