Rename -n/--no-window to -N/--no-display

The description of scrcpy is "Display and control your Android device".
We want an option to disable display, another one to disable control.

For naming consistency, name it --no-display.

Also change the shortname to -N, so that we can use -n for --no-control
later.

app/src/scrcpy.h

@@ -15,7 +15,7 @@ struct scrcpy_options {
     SDL_bool show_touches;
     SDL_bool fullscreen;
     SDL_bool always_on_top;
-    SDL_bool no_window;
+    SDL_bool no_display;
 };
 
 SDL_bool