rawinput, touch: attempt to remove touchscreens injecting mouse events (#687)

## Link to GitHub Issue or related Pull Request, if one exists
Fixes #562

## Description of change

### rawinput touch fixes
In rawinput touch handler, if the mouse events (`WM_LBUTTONDOWN`,
`WM_MOUSEMOVE`, `WM_LBUTTONUP`) originated from a touch screen, drop
them on the floor instead of treating them as touch events.

This is an attempt to fix phantom touch issues we see with some screens.

Fix another issue where, if mouse is clicked inside the window, and then
dragged outside the window and button is released, touch point (id 0)
continues to be held.

### wintouchemu fixes
If we detected a touch input recently (500ms), ignore new mouse clicks.
This isn't perfect, but hopefully it helps with filtering out mouse
clicks originating from touch screens.

Also, switch over to detecting the primary mouse button correctly, not
just the left mouse button.

### notes

Future investigation: are there really touchscreens that report a mouse
HID capability & insert mouse events? We could have a way to filter them
at rawinput level but it'll be ugly.

## Testing
Tried jubeat, beatstream..

src/spice2x/misc/wintouchemu.cpp

@@ -38,6 +38,9 @@ namespace wintouchemu {
     bool INJECT_MOUSE_AS_WM_TOUCH = false;
     bool LOG_FPS = false;
     bool ADD_TOUCH_FLAG_PRIMARY = false;
+    
+    // state
+    double last_touch_event = 0.0;
 
     static inline bool is_emu_enabled() {
         return FORCE || !is_touch_available("wintouchemu::is_emu_enabled") || GRAPHICS_SHOW_CURSOR;
@@ -248,7 +251,10 @@ namespace wintouchemu {
                         touch_input->y -= SPICETOUCH_TOUCH_Y;
                     }
 
-                    // log_misc("wintouchemu", "mouse state ({}, {})", to_string(touch_input->x), to_string(touch_input->y));
+                    // log_misc(
+                    //     "wintouchemu",
+                    //     "mouse state ({}, {}) event={}",
+                    //     to_string(touch_input->x), to_string(touch_input->y), mouse_state.touch_event);
 
                     auto valid = true;
                     if (overlay::OVERLAY) {
@@ -439,6 +445,8 @@ namespace wintouchemu {
             }
         }
 
+        const auto now = get_performance_milliseconds();
+
         // update touch events
         if (hWnd != nullptr) {
 
@@ -458,6 +466,7 @@ namespace wintouchemu {
 
             // check if new events are available
             if (event_count > 0) {
+                last_touch_event = now;
 
                 // send fake event to make the game update it's touch inputs
                 auto wndProc = (WNDPROC) GetWindowLongPtr(hWnd, GWLP_WNDPROC);
@@ -484,7 +493,12 @@ namespace wintouchemu {
         // value from GetTouchInputInfo or fail to read dwFlags for valid events, so it's not OK to
         // send empty events when the mouse button is not clicked/released
         if (hWnd != nullptr && USE_MOUSE) {
-            bool button_pressed = ((GetKeyState(VK_LBUTTON) & 0x100) != 0);
+            bool button_pressed = get_async_primary_mouse();
+
+            // if there was a touch event in the last 500 ms, don't insert new button presses
+            if (button_pressed && (now - last_touch_event) < 500) {
+                button_pressed = false;
+            }
 
             // figure out what kind of touch event to simulate
             if (button_pressed && !mouse_state.last_button_pressed) {