Add -Wextra-semi -Wundefined-func-template to the default CXXFLAGS

And fix the resulting compilation errors.

Change-Id: I16f679836a0cf2a3ff5dfcf6f6b67bfbfe4cdbd7
Refs: #4248
diff --git a/src/mgmt/nfd/face-event-notification.cpp b/src/mgmt/nfd/face-event-notification.cpp
index 79a94f2..653a9d9 100644
--- a/src/mgmt/nfd/face-event-notification.cpp
+++ b/src/mgmt/nfd/face-event-notification.cpp
@@ -61,11 +61,7 @@
   return totalLength;
 }
 
-template size_t
-FaceEventNotification::wireEncode<encoding::EncoderTag>(EncodingImpl<encoding::EncoderTag>& block) const;
-
-template size_t
-FaceEventNotification::wireEncode<encoding::EstimatorTag>(EncodingImpl<encoding::EstimatorTag>& block) const;
+NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(FaceEventNotification);
 
 const Block&
 FaceEventNotification::wireEncode() const