Add basic common_ui background gfx functions (#415)

* Add basic common_ui background gfx functions

* clang format

* document common_ui.h

* Remove unused tonc header

* Fix header guard name convention

* more header cleanup

* claaaaanggggg format

source/game/common_ui.c

@@ -0,0 +1,22 @@
+#include "game/common_ui.h"
+
+#include "game.h"
+
+typedef void (*BackgroundRenderCallback)(void);
+
+// Map to fill in for refactor
+BackgroundRenderCallback bgCallbacks[] =
+{
+    [BG_NONE] = NULL,
+    [BG_CARD_SELECTING] = NULL,
+    [BG_CARD_PLAYING] = NULL,
+    [BG_ROUND_END] = NULL,
+    [BG_SHOP] = NULL,
+    [BG_BLIND_SELECT] = NULL,
+    [BG_MAIN_MENU] = NULL,
+};
+
+void change_background(enum BackgroundId id)
+{
+    change_background_legacy(id);
+}