acio: detect crash during acio init due to RTSS/Afterburner and complain (#334)

## Link to GitHub Issue, if one exists
n/a

## Description of change
When an exception is caught during ACIO hook init, print a special
message to suggest the user to disable RTSS and MSI Afterburner, since
they are known to cause issues.

## Testing
Tried with RTSS enabled with High detection and with it disabled. Also
tried to crash the game a different way and check that the message is
not printed and the callstack is shown propeerly.

src/spice2x/acio/acio.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <atomic>
 #include <vector>
 
 #include <windows.h>
@@ -11,6 +12,7 @@ namespace acio {
     // globals
     extern HINSTANCE DLL_INSTANCE;
     extern std::vector<acio::ACIOModule *> MODULES;
+    extern std::atomic<bool> IO_INIT_IN_PROGRESS;
 
     void attach();
     void attach_icca();