VideoCommon: add function to serialize ShaderAsset to json

Source/Core/Common/JsonUtil.h

@@ -0,0 +1,26 @@
+// Copyright 2024 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <span>
+
+#include <picojson.h>
+
+// Ideally this would use a concept like, 'template <std::ranges::range Range>' to constrain it,
+// but unfortunately we'd need to require clang 15 for that, since the ranges library isn't
+// fully implemented until then, but this should suffice.
+
+template <typename Range>
+picojson::array ToJsonArray(const Range& data)
+{
+  picojson::array result;
+  result.reserve(std::size(data));
+
+  for (const auto& value : data)
+  {
+    result.emplace_back(static_cast<double>(value));
+  }
+
+  return result;
+}