[tma2] [Ongoing] Continue implementing modules for tma2. (#1388)

* cs: add stub sysmodule to host command shell server

* cs: implement logic for main (linker error paradise, for now)

* cs: implement more of the system module's skeleton

* htcs: update client type names for libnx pr merge

libraries/libstratosphere/include/stratosphere/scs/scs_shell.hpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <vapours.hpp>
+#include <stratosphere/os.hpp>
+#include <stratosphere/ncm/ncm_ids.hpp>
+
+namespace ams::scs {
+
+    using ProcessEventHandler = void(*)(u64 id, s32 socket, os::ProcessId process_id);
+
+    void InitializeShell();
+
+    void RegisterCommonProcessEventHandler(ProcessEventHandler on_start, ProcessEventHandler on_exit, ProcessEventHandler on_jit_debug);
+
+    bool RegisterSocket(s32 socket);
+    void UnregisterSocket(s32 socket);
+
+    Result LaunchProgram(os::ProcessId *out, ncm::ProgramId program_id, const void *args, size_t args_size, u32 process_flags);
+
+    Result SubscribeProcessEvent(s32 socket, bool is_register, u64 id);
+
+}