Add a "user controller" identifier/name to limits and/or mapping rules.

Working on the 3scale operator, we rely on matching the current limits and mapping rules in 3scale by iterating over all of them, and trying to find one that matches with the desired state by looking at the path, method, and metric.

We would like a more "efficient" way of checking this, by looking at a "given name"/identifier to simplify the reconciliation loop.

jprusi@redhat.com, can you give us a use case for this? Can you explain why you want a system name for each one and what kind of name you're thinking of?