Merge bitcoin/bitcoin#23006: multiprocess: Add new bitcoin-gui, bitcoin-qt, bitcoin-wallet init implementations

d5f985e51f multiprocess: Add new bitcoin-gui, bitcoin-qt, bitcoin-wallet init implementations (Russell Yanofsky)

Pull request description:

  Add separate `interfaces::Init` subclasses for `bitcoin-wallet`,  `bitcoin-gui`, and `bitcoin-qt` binaries instead of sharing `bitcoind` and `bitcoin-node` init subclasses in different binaries. After this, the new init subclasses can be customized in #10102, so node and wallet code is dropped from the `bitcoin-gui` binary and wallet code is dropped from into the `bitcoin-node` binary.

  ---

  This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).

ACKs for top commit:
  lsilva01:
    reACK d5f985e
  hebasto:
    re-ACK d5f985e51f, only suggested changes since my [previous](https://github.com/bitcoin/bitcoin/pull/23006#pullrequestreview-787537444) review.

Tree-SHA512: 6784210bd9ce3a6fbc66852680d0e9bc513c072dc538aeb7f48cb6a41580d3f567ccef04f975ee767a714a4b05d4d87273e94a79abda1b9c25d5ac4bbe752006

src/qt/bitcoin.cpp

@@ -13,7 +13,6 @@
 #include <interfaces/handler.h>
 #include <interfaces/init.h>
 #include <interfaces/node.h>
-#include <node/context.h>
 #include <node/ui_interface.h>
 #include <noui.h>
 #include <qt/bitcoingui.h>
@@ -464,9 +463,7 @@ int GuiMain(int argc, char* argv[])
     std::tie(argc, argv) = winArgs.get();
 #endif
 
-    NodeContext node_context;
-    int unused_exit_status;
-    std::unique_ptr<interfaces::Init> init = interfaces::MakeNodeInit(node_context, argc, argv, unused_exit_status);
+    std::unique_ptr<interfaces::Init> init = interfaces::MakeGuiInit(argc, argv);
 
     SetupEnvironment();
     util::ThreadSetInternalName("main");

src/qt/test/test_main.cpp

@@ -52,9 +52,7 @@ int main(int argc, char* argv[])
         BasicTestingSetup dummy{CBaseChainParams::REGTEST};
     }
 
-    NodeContext node_context;
-    int unused_exit_status;
-    std::unique_ptr<interfaces::Init> init = interfaces::MakeNodeInit(node_context, argc, argv, unused_exit_status);
+    std::unique_ptr<interfaces::Init> init = interfaces::MakeGuiInit(argc, argv);
     gArgs.ForceSetArg("-listen", "0");
     gArgs.ForceSetArg("-listenonion", "0");
     gArgs.ForceSetArg("-discover", "0");