* refactor: discovery protocols re-write
extract more code to make it easier to read
use snmpwalk_group
walk lldpRemTable instead of lldpRemoteSystemsData
Optimize discover_device to reduce dns lookups of bad dns names
Make discovery_by_ip behavior consistent between cdp and lldp
move can_skip_discovery to discovery functions
Tested lldp, cdp, and ospf.
* always discover links even if the remote device isn't in system
Fix discover_link always updating
* fix style
* fix update, not fetching id
* increase platform length. Most devices use sysDescr here, which is max length 255
* remove orphaned links
* update db_schema.yaml
