Add Firmware 20.0.0-21.0.0 IPC support and stubs

This commit implements comprehensive firmware 20.0.0 through 21.0.0
support for Citron, including:

- Updated firmware version constants to 21.0.0 in api_version.h
- Updated HID service firmware version string to 21.0.0
- Added IPC command stubs for firmware 20.0.0+ in:
  * ISystemSettingsServer (commands 263, 264, 282, 283, 289, 300, 301, 306, 307)
  * IFirmwareDebugSettingsServer (command 24)
  * IApplicationFunctions (command 330)
  * IOlscServiceForSystemService (command 914)
  * IRemoteStorageController (commands 28, 901)
  * IService (migration) (commands 2250, 2260)
  * IAudioController (command 10200)

- Created new service interfaces with proper stubs:
  * IContinuousRecorder (grcsrv) - command 5 [20.2.0+] with 0x20-byte input
  * IDownloadContext (news) - command 4 [20.0.0+]
  * INotifyService (pdm:ntfy) - commands 100, 101 [20.0.0+] returning outinterfaces

- Added all new source files to CMakeLists.txt build system
- Fixed logging tag usage (Service_Migration instead of Service_MIG)
- Added required CMIF serialization headers for proper template instantiation

All stubs return success explicitly, eliminating the need for auto-stubbing.
All implementations follow Switchbrew documentation as closely as possible.

Based on Switchbrew documentation:
- https://switchbrew.org/wiki/21.0.0
- https://switchbrew.org/wiki/20.5.0
- https://switchbrew.org/wiki/20.4.0
- https://switchbrew.org/wiki/20.3.0
- https://switchbrew.org/wiki/20.2.0
- https://switchbrew.org/wiki/20.1.5
- https://switchbrew.org/wiki/20.1.1
- https://switchbrew.org/wiki/20.1.0
- https://switchbrew.org/wiki/20.0.1
- https://switchbrew.org/wiki/20.0.0

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/core/hle/service/mig/mig.cpp

@@ -1,8 +1,11 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <memory>
 
+#include "common/logging/log.h"
+#include "core/hle/service/cmif_serialization.h"
 #include "core/hle/service/mig/mig.h"
 #include "core/hle/service/server_manager.h"
 #include "core/hle/service/service.h"
@@ -24,14 +27,30 @@ public:
             {1100, nullptr, "Unknown1100"},
             {1101, nullptr, "Unknown1101"},
             {1200, nullptr, "Unknown1200"},
-            {1201, nullptr, "Unknown1201"}
+            {1201, nullptr, "Unknown1201"},
+            {2250, D<&MIG_USR::Unknown2250>, "Unknown2250"}, // [20.2.0+] interface version updated
+            {2260, D<&MIG_USR::Unknown2260>, "Unknown2260"}, // [20.2.0+] interface version updated
         };
         // clang-format on
 
         RegisterHandlers(functions);
     }
+
+private:
+    Result Unknown2250();
+    Result Unknown2260();
 };
 
+Result MIG_USR::Unknown2250() {
+    LOG_WARNING(Service_Migration, "(STUBBED) called Unknown2250 [20.2.0+]");
+    R_SUCCEED();
+}
+
+Result MIG_USR::Unknown2260() {
+    LOG_WARNING(Service_Migration, "(STUBBED) called Unknown2260 [20.2.0+]");
+    R_SUCCEED();
+}
+
 void LoopProcess(Core::System& system) {
     auto server_manager = std::make_unique<ServerManager>(system);