Move Win32 bindings into runtime state

src/platform_windows/windows_runtime_shell.cpp

@@ -10,32 +10,9 @@
 #include "platform_windows/windows_runtime_state.h"
 #include "platform_windows/windows_stylus_input.h"
 #include "platform_windows/windows_window_shell.h"
-#include "wacom.h"
 
 namespace pp::platform::windows {
 
-void bind_app(App* app) noexcept
-{
-    App::I = app;
-}
-
-App* bound_app() noexcept
-{
-    return App::I;
-}
-
-void release_bound_app() noexcept
-{
-    bind_app(nullptr);
-    bind_runtime(nullptr);
-    retained_owned_app().reset();
-}
-
-WacomTablet* bound_wacom_tablet() noexcept
-{
-    return &retained_wacom_tablet();
-}
-
 int run_main_application(int argc, char** argv)
 {
     const auto instance = GetModuleHandle(NULL);