1. Proposed title of this feature request
Implement new monitoring alerts for OVNKubernetes troubleshooting

2. What is the nature and description of the request?
At the moment OCP cluster doesn't have enough alerts for admins to be aware of possible critical issues with OVN services and configuration so they can proactively trace them.
Some alerts that might be useful to implement would be:

• Alerts generated/operator degraded with the OVN NB database becomes larger than expected or other inconsistencies with nbdb databases.
• Alerts generated/operator degraded when OVN has split brain (eg. southbound/northbound roles as candidate, different cluster IDs etc).
• Alert generated when you have more EgressFirewall rules than permitted in the documentation - https://docs.openshift.com/container-platform/4.9/networking/ovn_kubernetes_network_provider/configuring-egress-firewall-ovn.html#limitations-of-an-egress-firewall_configuring-egress-firewall-ovn

3. Why does the customer need this? (List the business requirements here)
Many and many customers are adopting OVNKubernetes and due to complexity of OVN stack customers need extra monitoring capabilities to be aware of possible issues in OVN.

4. List any affected packages or components.
OVNKubernetes