Provide a method to verify topology capability

For each of the layer 2 or layer 3 topology discovery protocols, we document the SNMP OIDs used to fetch the data from which the topology is built:

https://docs.opennms.com/horizon/30/operation/topology/enlinkd/layer-2/lldp-discovery.html

https://docs.opennms.com/horizon/30/operation/topology/enlinkd/layer-2/cdp-discovery.html

https://docs.opennms.com/horizon/30/operation/topology/enlinkd/layer-2/bridge-discovery.html

etc.

It is cumbersome and error prone for a user, or a layperson, or network engineer, to snmpget / walk on each documented OID to verify the discovery protocol data on which enlinkd relies is available.

As these OIDs are known, we should provide a method (preferably a Karaf shell command) to verify a given node exposes the correct OIDs for a given link discovery protocol via the Karaf shell.