ovn-k ACL indexing refactoring

ACL.Name is trimmed for logging reasons, we can't use it as ID anymore https://issues.redhat.com/browse/OCPBUGS-1958
We need to develop a new set of IDs for ACLs, that will

• uniquely identify db object
• be build based on the k8s object fields
• remove the need in isEquivalentACL, which is an artificial db index
• allow to have multiple ACLs with the same priority+direction+match+action (for shared network policy port groups)
• allow to identify the owner of the db entry to ensure proper cleanup
• allow to use secondary indices for better search performance