Discovery: split node records to a sepatate DB table (#3581) (#3667)

Problem:
QuerySeeds will poke 150 random entries in the whole node DB and ignore hitting "field" entries.
In a bootstrap scenario it might hit hundreds of :lastping :lastpong entries,
and very few true "node record" entries.
After running for 15 minutes I've got totalEntryCount=1508 nodeRecordCount=114 entries.
There's a 1/16 chance of hitting a "node record" entry.
It means finding just about 10 nodes of 114 total on average from 150 attempts.

Solution:
Split "node record" entries to a separate table such that QuerySeeds doesn't do idle cycle hits.