Undo PokeCodec's PRs

This commit undoes most of PokeCodec's PRs after the debate in chat. Some
harmless or completely superseded PRs have been left alone, as there is not
much benefit in attempting to undo them.

Reverts #1104, #1108, #1115, #1118, #1119, #1124, #1126, #1127, #1132, #1136,
#1137, #1139, #1140, #1144, #1148, #1149, #1150, #1153, #1155, #1177, #1179,
#1180, #1181, #1182 and #1183.

src/battle_ai_script_commands.c

@@ -1299,7 +1299,7 @@ static void Cmd_count_usable_party_mons(void)
 
     if (gBattleTypeFlags & BATTLE_TYPE_DOUBLE)
     {
-        u8 position;
+        u32 position;
         battlerOnField1 = gBattlerPartyIndexes[battlerId];
         position = GetBattlerPosition(battlerId) ^ BIT_FLANK;
         battlerOnField2 = gBattlerPartyIndexes[GetBattlerAtPosition(position)];