luci-mod-status: aid DNS lookups with /etc/ethers

luci-mod-status: aid DNS lookups with /etc/ethers

- Integrate luci-rpc.getHostHints for host-hints lookup
- Stop mutating lookup_queue during iteration; use Set + filter()
  to remove resolved entries safely
- Collect unresolved addresses, consult host hints, and apply hinted names
- Use explicit defaults for recheck counters

Rationale:

Host hints provide a low-cost way to resolve IPv6 SLAAC and link-local
addresses, improving lookup coverage.

Bug fixes:

Removing elements from lookup_queue with splice() while iterating
reduced_lookup_queue could remove wrong indices or skip entries.
Switching to filter() and a Set fixes this class of logic bugs.

Signed-off-by: Konstantin Glukhov <redacted>