[RFE] add support to view OVN DB

[cpassare]

When OVNKubernetes is in use the must-gather collect SB and NB DBs from the OVN leaders. Would be nice to have the possibility to query both databases using omc. The databases are collected in the following files:

• network_logs/leader_nbdb.gz
• network_logs/leader_sbdb.gz

The following are the scripts generally used to read locally the databases:

• https://github.com/openshift/dev-knowledge-base/blob/master/scripts/helpers/run_ovndb_in_container.sh
• https://github.com/openshift/dev-knowledge-base/blob/master/scripts/dev-run-ovndb