Add IW4 asset loader classes for all asset types that did not have one yet

src/ObjLoading/Game/IW4/AssetLoaders/AssetLoaderFx.cpp

@@ -0,0 +1,17 @@
+#include "AssetLoaderFx.h"
+
+#include <cstring>
+
+#include "ObjLoading.h"
+#include "Game/IW4/IW4.h"
+#include "Pool/GlobalAssetPool.h"
+
+using namespace IW4;
+
+void* AssetLoaderFx::CreateEmptyAsset(const std::string& assetName, MemoryManager* memory)
+{
+    auto* fx = memory->Create<FxEffectDef>();
+    memset(fx, 0, sizeof(FxEffectDef));
+    fx->name = memory->Dup(assetName.c_str());
+    return fx;
+}