chore: replace material dumping with lib recommendation of serializing and deserializing json

src/ObjCommon/Utils/JsonOptional.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <nlohmann/json.hpp>
+#include <optional>
+
+// partial specialization (full specialization works too)
+namespace nlohmann
+{
+    template<typename T> struct adl_serializer<std::optional<T>>
+    {
+        static void to_json(json& j, const std::optional<T>& opt)
+        {
+            if (!opt.has_value())
+            {
+                j = nullptr;
+            }
+            else
+            {
+                j = *opt; // this will call adl_serializer<T>::to_json which will
+                          // find the free function to_json in T's namespace!
+            }
+        }
+
+        static void from_json(const json& j, std::optional<T>& opt)
+        {
+            if (j.is_null())
+            {
+                opt = std::nullopt;
+            }
+            else
+            {
+                opt = j.template get<T>(); // same as above, but with
+                                           // adl_serializer<T>::from_json
+            }
+        }
+    };
+} // namespace nlohmann