Adapt to changes in Ghoul regarding string_view

Fix compile error if Trace logging is not enabled
Limit the number of threads to a maximum of 4 for asset initialization

modules/server/src/connection.cpp

@@ -207,10 +207,14 @@ void Connection::handleJson(const nlohmann::json& json) {
 }
 
 void Connection::sendMessage(const std::string& message) {
+    ZoneScoped
+
     _socket->putMessage(message);
 }
 
 void Connection::sendJson(const nlohmann::json& json) {
+    ZoneScoped
+
     sendMessage(json.dump());
 }