Implement an object backed IStorage backing

This is more convinient and efficient to use when passing structured data out of applets

app/src/main/cpp/skyline/services/am/storage/ObjIStorage.h

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2022 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#pragma once
+
+#include <services/serviceman.h>
+#include "IStorage.h"
+
+namespace skyline::service::am {
+    /**
+     * @brief ObjIStorage is an IStorage backed by a trivially copyable object
+     */
+    template<typename T> requires std::is_trivially_copyable_v<T>
+    class ObjIStorage : public IStorage {
+      private:
+        T obj;
+
+      public:
+        ObjIStorage(const DeviceState &state, ServiceManager &manager, T &&obj) :  IStorage(state, manager, true), obj(obj) {}
+
+        ~ObjIStorage() override = default;
+
+        span<u8> GetSpan() override {
+            return {reinterpret_cast<u8 *>(&obj), sizeof(T)};
+        };
+    };
+}