Support for swapping two creatures on a side.

Signed-off-by: Deukhoofd <Deukhoofd@gmail.com>

CInterface/Battling/BattleSide.cpp

@@ -37,4 +37,8 @@ export uint8_t CreatureLib_BattleSide_MarkSlotAsUnfillable(BattleSide* p, Creatu
 
 export bool CreatureLib_BattleSide_IsDefeated(BattleSide* p) { return p->IsDefeated(); }
 export bool CreatureLib_BattleSide_HasFled(BattleSide* p) { return p->HasFled(); }
-export void CreatureLib_BattleSide_MarkAsFled(BattleSide* p) { p->MarkAsFled(); }
+export void CreatureLib_BattleSide_MarkAsFled(BattleSide* p) { p->MarkAsFled(); }
+
+export u8 CreatureLib_BattleSide_SwapPositions(u8& out, BattleSide* p, u8 a, u8 b) {
+    Try(out = p->SwapPositions(a, b);)
+}