popn: subscreen overlay (#631)

## Link to GitHub Issue or related Pull Request, if one exists
#618 

## Description of change

Add overlay for subscreen.

Add an option for no subscreen window.

Use the same "force redraw subscreen" logic we used in SDVX to fix the
same issue.

Known issues:

* still crashing when running windowed if there is only one monitor
* having only one monitor causes sunscreen overlay to not work
(NumberOfAdaptersInGroup issue?)

## Testing

src/spice2x/hooks/graphics/graphics.cpp

@@ -16,6 +16,7 @@
 #include "games/ddr/ddr.h"
 #include "games/gitadora/gitadora.h"
 #include "games/iidx/iidx.h"
+#include "games/popn/popn.h"
 #include "hooks/graphics/backends/d3d9/d3d9_backend.h"
 #include "launcher/shutdown.h"
 #include "overlay/overlay.h"
@@ -401,7 +402,9 @@ static HWND WINAPI CreateWindowExA_hook(DWORD dwExStyle, LPCSTR lpClassName, LPC
 
     if (is_popn_sub_window) {
         POPN_SUBSCREEN_WINDOW = result;
-        graphics_hook_subscreen_window(POPN_SUBSCREEN_WINDOW);
+        if (!GRAPHICS_PREVENT_SECONDARY_WINDOW) {
+            graphics_hook_subscreen_window(POPN_SUBSCREEN_WINDOW);
+        }
     }
 
     disable_touch_indicators(result);
@@ -671,6 +674,13 @@ static BOOL WINAPI ShowWindow_hook(HWND hWnd, int nCmdShow) {
         return true;
     }
 
+    if (games::popn::is_pikapika_model() &&
+        GRAPHICS_PREVENT_SECONDARY_WINDOW &&
+        hWnd == POPN_SUBSCREEN_WINDOW) {
+        log_info("graphics", "ShowWindow_hook - hiding sub window {}", fmt::ptr(hWnd));
+        return true;
+    }
+
     // call original
     return ShowWindow_orig(hWnd, nCmdShow);
 }