feat: add DevUtilBackend with GetFilamentDryingPreset

Reads filament_dev_ams_drying_* config keys from filament presets
and returns structured DevFilamentDryingPreset data.

src/slic3r/GUI/DeviceCore/DevUtilBackend.h

@@ -0,0 +1,26 @@
+/**
+ * @file DevUtilBackend.h
+ * @brief Provides common static utility methods for backend (preset/slicing).
+ */
+
+#pragma once
+#include "DevDefs.h"
+#include "DevFilaSystem.h"
+
+#include <optional>
+#include <string>
+
+namespace Slic3r
+{
+
+class DevUtilBackend
+{
+public:
+    DevUtilBackend() = delete;
+
+public:
+    // for filament preset
+    static std::optional<DevFilamentDryingPreset> GetFilamentDryingPreset(const std::string& fila_id);
+};
+
+}; // namespace Slic3r