ipc: Add MakeBasicInit function

Add a MakeBasicInit() function so simpler standalone IPC clients like
bitcoin-mine in #30437 and bitcoin-cli in #32297 that only initiate IPC
connections without exposing any IPC interfaces themselves can to avoid needing
to implement their own specialized interfaces::Init subclasses.

src/init/basic.cpp

@@ -0,0 +1,26 @@
+// Copyright (c) 2025 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <interfaces/init.h>
+#include <interfaces/ipc.h>
+
+namespace init {
+namespace {
+class BitcoinBasicInit : public interfaces::Init
+{
+public:
+    BitcoinBasicInit(const char* exe_name, const char* process_argv0) : m_ipc(interfaces::MakeIpc(exe_name, process_argv0, *this)) {}
+    interfaces::Ipc* ipc() override { return m_ipc.get(); }
+private:
+    std::unique_ptr<interfaces::Ipc> m_ipc;
+};
+} // namespace
+} // namespace init
+
+namespace interfaces {
+std::unique_ptr<Init> MakeBasicInit(const char* exe_name, const char* process_argv0)
+{
+    return std::make_unique<init::BitcoinBasicInit>(exe_name, process_argv0);
+}
+} // namespace interfaces