core: slim down `common.hpp`

Change-Id: I875c35147edd2261fbaa24e809c170d5cd9b94d3
diff --git a/core/common.hpp b/core/common.hpp
index cc999d8..06b8ede 100644
--- a/core/common.hpp
+++ b/core/common.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  Regents of the University of California,
+ * Copyright (c) 2014-2024,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -46,12 +46,8 @@
 
 #include <cstddef>
 #include <cstdint>
-#include <functional>
-#include <limits>
-#include <map>
 #include <memory>
 #include <optional>
-#include <set>
 #include <stdexcept>
 #include <string>
 #include <string_view>
@@ -63,10 +59,8 @@
 #include <ndn-cxx/name.hpp>
 #include <ndn-cxx/encoding/block.hpp>
 #include <ndn-cxx/lp/nack.hpp>
-#include <ndn-cxx/net/face-uri.hpp>
 #include <ndn-cxx/util/backports.hpp>
 #include <ndn-cxx/util/exception.hpp>
-#include <ndn-cxx/util/scheduler.hpp>
 #include <ndn-cxx/util/signal.hpp>
 #include <ndn-cxx/util/span.hpp>
 #include <ndn-cxx/util/time.hpp>
@@ -84,11 +78,6 @@
 using std::make_shared;
 using std::make_unique;
 
-using std::static_pointer_cast;
-using std::dynamic_pointer_cast;
-using std::const_pointer_cast;
-
-using std::to_string;
 using namespace std::string_literals;
 using namespace std::string_view_literals;
 
@@ -97,11 +86,9 @@
 using ndn::span;
 using ndn::Block;
 using ndn::Data;
-using ndn::FaceUri;
 using ndn::Interest;
 using ndn::Name;
 using ndn::PartialName;
-using ndn::Scheduler;
 
 // Not using a namespace alias (namespace tlv = ndn::tlv), because
 // it doesn't allow NFD to add other members to the namespace
@@ -111,7 +98,6 @@
 
 namespace lp = ndn::lp;
 namespace name = ndn::name;
-namespace scheduler = ndn::scheduler;
 namespace signal = ndn::signal;
 namespace time = ndn::time;