System: Move GDB server into core

src/core/gdb_server.h

@@ -0,0 +1,14 @@
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com> and contributors.
+// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
+
+#pragma once
+#include <string_view>
+
+namespace GDBServer {
+bool Initialize(u16 port);
+bool HasAnyClients();
+void Shutdown();
+
+void OnSystemPaused();
+void OnSystemResumed();
+} // namespace GDBServer