touch: restore wintouchemu, fall back to it when native touch hooks fail (#834)

## Link to GitHub Issue or related Pull Request, if one exists
Fixes #833

## Description of change
Last couple PRs - such as #820 #827 #828 - made the native touch hook &
touch injection using `InjectTouchInput` the default path, since it
performs much more reliably with both real touch screens and mouse (or
any other synthetic source).

However, user has reported that WINE lacks `InjectTouchInput` which
means this won't work.

As a fix, revive the old wintouchemu code. Native touch is still the
default, but under following circumstances:

1. if `-touchemuforce` is set, or
2. if any of the required Windows touch APIs are unavailable

then we fail over from native touch to wintouchemu code. 

For Linux, condition #2 would be hit during init, and gracefully switch
over.

Caveat: the poke code for IIDX and Nost will continue to require native
touch, I do not want to maintain two paths for this. This means that
iidx poke will stop working on Linux, unfortunately.

## Testing
Tested on Windows with `-touchemuforce` set. This is mostly reverting
Linux code path back to where we were last release, so this should just
work with wine.

src/spice2x/games/iidx/poke.cpp

@@ -4,6 +4,7 @@
 
 #include "windows.h"
 #include "games/io.h"
+#include "games/iidx/iidx.h"
 #include "hooks/graphics/graphics.h"
 #include "launcher/shutdown.h"
 #include "misc/eamuse.h"
@@ -116,6 +117,11 @@ namespace games::iidx::poke {
         if (THREAD)
             return;
 
+        if (!games::iidx::NATIVE_TOUCH) {
+            log_warning("poke", "keypad touch emulation requires native touch; disabled");
+            return;
+        }
+
         // create new thread
         THREAD_RUNNING = true;
         THREAD = new std::thread([] {