yuzu-cmd: hide cursor when in fullscreen

Exposed the SDL_ShowCursor function to EmuWindow baseclass. When creating the window (GL or VK) in fullscreen it now automatically hides the cursor.

src/yuzu_cmd/emu_window/emu_window_sdl2.cpp

@@ -122,6 +122,10 @@ void EmuWindow_SDL2::OnResize() {
     UpdateCurrentFramebufferLayout(width, height);
 }
 
+void EmuWindow_SDL2::ShowCursor(bool show_cursor) {
+    SDL_ShowCursor(show_cursor ? SDL_ENABLE : SDL_DISABLE);
+}
+
 void EmuWindow_SDL2::Fullscreen() {
     switch (Settings::values.fullscreen_mode.GetValue()) {
     case Settings::FullscreenMode::Exclusive: