Add PR_RTL_XFLIP to some important places

Okay, the "Font:" thing needed some local code after all, because both
the interface font as well as the level font are used there. But it's
good enough - all the other places can just use the flag.

Notably, I also used this for the menus, since the existing ones are
kinda LTR-oriented, and it's something that we don't *really* have to
do, but I think it shows we care!

desktop_version/src/Game.h

@@ -6,6 +6,7 @@
 #include <string>
 #include <vector>
 
+#include "Font.h"
 #include "ScreenSettings.h"
 
 /* FIXME: Can't forward declare this enum in C++, unfortunately.
@@ -382,7 +383,7 @@ public:
     int menuspacing;
     std::vector<MenuStackFrame> menustack;
 
-    void inline option(const char* text, bool active = true, uint32_t print_flags = 0)
+    void inline option(const char* text, bool active = true, uint32_t print_flags = PR_RTL_XFLIP)
     {
         MenuOption menuoption;
         SDL_strlcpy(menuoption.text, text, sizeof(menuoption.text));