Improves build process for internal development

Adds an INTERNAL preprocessor definition to manage dependencies.

This change allows for a lighter build during internal development by
forward declaring some classes and excluding UI and CAN dependencies.

server/simulator_base.cpp

@@ -1,4 +1,6 @@
+#define INTERNAL
 #include "simulator_base.hpp"
+#include "ui_item.hpp"
 
 Simulator_base::Simulator_base(std::string name, Communication *com, std::chrono::milliseconds interval,
                                QObject *parent)

server/simulator_base.hpp

@@ -1,12 +1,21 @@
 #pragma once
 
-#include "UI.hpp"
 #include "spdlog/spdlog.h"
-#include "ui.hpp"
 #include <QSerialPort>
 #include <QThread>
 #include <QTimer>
 
+#ifndef INTERNAL
+#include "ui.hpp"
+#else
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+Q_FORWARD_DECLARE_OBJC_CLASS(CAN_Wrapper);
+Q_FORWARD_DECLARE_OBJC_CLASS(UI_item);
+#endif
+
 #define PUSH_UI_ITEM(item) push_ui_item(&item)
 #define EXPORT_SIM(sim)                                                                                                \
     extern "C" Q_DECL_EXPORT Simulator_base *get_sim(Communication *com, QObject *parent)                              \