Return EXIT_FAILURE on post-init fatal errors

It seems odd to return `EXIT_SUCCESS` when the node aborted
execution due a fatal internal error or any post-init problem
that triggers an unrequested shutdown.

e.g. blocks or coins db I/O errors, disconnect block failure,
failure during thread import (external blocks loading process
error), among others.

Co-authored-by: Ryan Ofsky <ryan@ofsky.org>

src/init.cpp

@@ -800,7 +800,7 @@ std::set<BlockFilterType> g_enabled_filter_types;
     std::terminate();
 };
 
-bool AppInitBasicSetup(const ArgsManager& args)
+bool AppInitBasicSetup(const ArgsManager& args, std::atomic<int>& exit_status)
 {
     // ********************************************************* Step 1: setup
 #ifdef _MSC_VER
@@ -814,7 +814,7 @@ bool AppInitBasicSetup(const ArgsManager& args)
     // Enable heap terminate-on-corruption
     HeapSetInformation(nullptr, HeapEnableTerminationOnCorruption, nullptr, 0);
 #endif
-    if (!InitShutdownState()) {
+    if (!InitShutdownState(exit_status)) {
         return InitError(Untranslated("Initializing wait-for-shutdown state failed."));
     }