fw: increment nOutNacks when sending a Nack from onInterestLoop

Also expand test coverage of all forwarder counters

Change-Id: I6948af05aca1b5589e2f1c8a1f23c002d39d0ec0
diff --git a/daemon/fw/forwarder-counters.hpp b/daemon/fw/forwarder-counters.hpp
index d6b2fde..c1242e1 100644
--- a/daemon/fw/forwarder-counters.hpp
+++ b/daemon/fw/forwarder-counters.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  Regents of the University of California,
+ * Copyright (c) 2014-2023,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -30,7 +30,8 @@
 
 namespace nfd {
 
-/** \brief Counters provided by Forwarder
+/**
+ * \brief Counters provided by Forwarder.
  */
 class ForwarderCounters
 {