[ndnSIM] util: Redirect logger to use the logging facility of NS3

This commit also includes:

1) Disambiguation of logging component name of CertificateFetcherFromNetwork
2) Addition of the "ndn-cxx." prefix

Change-Id: Ib345978575104afa436296d2f5a824a39e3a9721
diff --git a/src/security/v2/certificate-fetcher-from-network.cpp b/src/security/v2/certificate-fetcher-from-network.cpp
index 5d7bcaa..8c4d362 100644
--- a/src/security/v2/certificate-fetcher-from-network.cpp
+++ b/src/security/v2/certificate-fetcher-from-network.cpp
@@ -27,7 +27,7 @@
 namespace security {
 namespace v2 {
 
-NDN_LOG_INIT(ndn.security.v2.CertificateFetcher);
+NDN_LOG_INIT(ndn.security.v2.CertificateFetcher.FromNetwork);
 
 #define NDN_LOG_DEBUG_DEPTH(x) NDN_LOG_DEBUG(std::string(state->getDepth() + 1, '>') << " " << x)
 #define NDN_LOG_TRACE_DEPTH(x) NDN_LOG_TRACE(std::string(state->getDepth() + 1, '>') << " " << x)