re-match BattleIntroOpponent1SendsOutMonAnimation

a lot of functions and a bit of data had to be moved from battle_main.c
to battle_util.c; I have added a note to battle_util.c stating the
reason for this

include/battle_main.h

@@ -83,6 +83,7 @@ u8 GetWhoStrikesFirst(u8 battlerId1, u8 battlerId2, bool8 ignoreChosenMoves);
 void RunBattleScriptCommands_PopCallbacksStack(void);
 void RunBattleScriptCommands(void);
 bool8 TryRunFromBattle(u8 battlerId);
+void SpecialStatusesClear(void);
 
 extern struct UnknownPokemonStruct4 gMultiPartnerParty[MULTI_PARTY_SIZE];