server: Add connection as part of a request

Source/cmServer.cxx

@@ -83,7 +83,7 @@ void cmServer::ProcessRequest(cmConnection* connection,
     debug->PrintStatistics = debugValue["showStats"].asBool();
   }
 
-  const cmServerRequest request(this, value[kTYPE_KEY].asString(),
+  const cmServerRequest request(this, connection, value[kTYPE_KEY].asString(),
                                 value[kCOOKIE_KEY].asString(), value);
 
   if (request.Type == "") {
@@ -323,7 +323,7 @@ void cmServer::WriteProgress(const cmServerRequest& request, int min,
   obj[kPROGRESS_MAXIMUM_KEY] = max;
   obj[kPROGRESS_CURRENT_KEY] = current;
 
-  this->WriteJsonObject(obj, nullptr);
+  this->WriteJsonObject(request.Connection, obj, nullptr);
 }
 
 void cmServer::WriteMessage(const cmServerRequest& request,
@@ -343,7 +343,7 @@ void cmServer::WriteMessage(const cmServerRequest& request,
     obj[kTITLE_KEY] = title;
   }
 
-  WriteJsonObject(obj, nullptr);
+  WriteJsonObject(request.Connection, obj, nullptr);
 }
 
 void cmServer::WriteParseError(cmConnection* connection,

Source/cmServerProtocol.cxx

@@ -125,11 +125,13 @@ void getCMakeInputs(const cmGlobalGenerator* gg, const std::string& sourceDir,
 
 } // namespace
 
-cmServerRequest::cmServerRequest(cmServer* server, const std::string& t,
-                                 const std::string& c, const Json::Value& d)
+cmServerRequest::cmServerRequest(cmServer* server, cmConnection* connection,
+                                 const std::string& t, const std::string& c,
+                                 const Json::Value& d)
   : Type(t)
   , Cookie(c)
   , Data(d)
+  , Connection(connection)
   , m_Server(server)
 {
 }

Source/cmServerProtocol.h

@@ -11,6 +11,7 @@
 #include <string>
 #include <utility>
 
+class cmConnection;
 class cmFileMonitor;
 class cmServer;
 class cmServerRequest;
@@ -52,9 +53,11 @@ public:
   const std::string Type;
   const std::string Cookie;
   const Json::Value Data;
+  cmConnection* Connection;
 
 private:
-  cmServerRequest(cmServer* server, const std::string& t, const std::string& c,
+  cmServerRequest(cmServer* server, cmConnection* connection,
+                  const std::string& t, const std::string& c,
                   const Json::Value& d);
 
   void ReportProgress(int min, int current, int max,