Add controller button layout mappings

This adds mappings from SDL's Xbox-based SDL_GameControllerButton
constants, to glyphs for the following layouts:

- LAYOUT_NINTENDO_SWITCH_PRO,
- LAYOUT_NINTENDO_SWITCH_JOYCON_L,
- LAYOUT_NINTENDO_SWITCH_JOYCON_R,
- LAYOUT_DECK,
- LAYOUT_PLAYSTATION,
- LAYOUT_XBOX,
- LAYOUT_GENERIC,

There may still be errors in these, but they should be mostly correct.
I'm leaving it up to Ethan to make it show the correct button glyphs
for the correct controllers being connected (and possibly to fix these
mappings where needed).

desktop_version/src/ButtonGlyphs.h

@@ -1,6 +1,7 @@
 #ifndef BUTTONGLYPHS_H
 #define BUTTONGLYPHS_H
 
+#include <SDL.h>
 #include <stdbool.h>
 
 #include "ActionSets.h"
@@ -15,7 +16,14 @@ void BUTTONGLYPHS_init(void);
 bool BUTTONGLYPHS_keyboard_is_available(void);
 bool BUTTONGLYPHS_keyboard_is_active(void);
 const char* BUTTONGLYPHS_get_wasd_text(void);
-const char* BUTTONGLYPHS_get_button(ActionSet actionset, Action action);
+const char* BUTTONGLYPHS_get_button(ActionSet actionset, Action action, int binding);
+
+char* BUTTONGLYPHS_get_all_gamepad_buttons(
+    char* buffer,
+    size_t buffer_len,
+    ActionSet actionset,
+    int action
+);
 
 #ifdef __cplusplus
 } // extern "C"