nost: move nostalgia from wintouchemu to native touch hook (#827)

## Link to GitHub Issue or related Pull Request, if one exists
#814

## Description of change
Switch over Nostalgia from wintouchemu to native touch hook.

Nostalgia has some strict timing requirements (touches must be updated
on every acio poll) so this takes a slightly different path to maintain
mouse holds.

Only a handful of consumers of wintouchemu remain:

1. beatstream - but it's off by default, only enabled as errata for
buggy touchscreens, or if the user forces it on (for Show Cursor)
2. gitadora single-window overlay - this is just for mouse so not a big
deal.
3. MFC HG mode - not a priority to fix.

## Testing
Tested full screen and windowed mode with touch / mouse / poke.

src/spice2x/misc/wintouchemu.h

@@ -10,6 +10,6 @@ namespace wintouchemu {
     extern bool LOG_FPS;
     extern bool ADD_TOUCH_FLAG_PRIMARY;
 
-    void hook(const char *window_title, HMODULE module = nullptr, int delay_in_s=0);
+    void hook(const char *window_title, HMODULE module = nullptr);
     void update();
 }