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_gl.cpp

@@ -111,6 +111,7 @@ EmuWindow_SDL2_GL::EmuWindow_SDL2_GL(InputCommon::InputSubsystem* input_subsyste
 
     if (fullscreen) {
         Fullscreen();
+        ShowCursor(false);
     }
 
     window_context = SDL_GL_CreateContext(render_window);