VideoCommon: pass a graphics mod base path to the graphics mod, so it can lookup other relative files if necessary

Source/Core/VideoCommon/GraphicsModSystem/Runtime/GraphicsModManager.cpp

@@ -8,6 +8,7 @@
 #include <variant>
 
 #include "Common/Logging/Log.h"
+#include "Common/StringUtil.h"
 #include "Common/VariantUtil.h"
 
 #include "Core/ConfigManager.h"
@@ -198,7 +199,10 @@ void GraphicsModManager::Load(const GraphicsModGroupConfig& config)
       const auto create_action =
           [](const std::string_view& action_name, const picojson::value& json_data,
              GraphicsModConfig mod_config) -> std::unique_ptr<GraphicsModAction> {
-        auto action = GraphicsModActionFactory::Create(action_name, json_data);
+        std::string base_path;
+        SplitPath(mod_config.GetAbsolutePath(), &base_path, nullptr, nullptr);
+
+        auto action = GraphicsModActionFactory::Create(action_name, json_data, base_path);
         if (action == nullptr)
         {
           return nullptr;