fix: seen flags for first mon in enemy party (#7791)

Co-authored-by: Alex <93446519+AlexOn1ine@users.noreply.github.com>

include/battle.h

@@ -600,7 +600,8 @@ struct PartyState
     u32 supersweetSyrup:1;
     u32 timesGotHit:5;
     u32 changedSpecies:11; // For forms when multiple mons can change into the same pokemon.
-    u32 padding:10;
+    u32 sentOut:1;
+    u32 padding:9;
 };
 
 // Cleared at the beginning of the battle. Fields need to be cleared when needed manually otherwise.

include/config/battle.h

@@ -311,6 +311,7 @@
 #define B_TOXIC_REVERSAL                GEN_LATEST // In Gen5+, bad poison will change to regular poison at the end of battles.
 #define B_TRY_CATCH_TRAINER_BALL        GEN_LATEST // In Gen4+, trying to catch a Trainer's Pokémon does not consume the Poké Ball.
 #define B_SLEEP_CLAUSE                  FALSE      // Enables Sleep Clause all the time in every case, overriding B_FLAG_SLEEP_CLAUSE. Use that for modularity.
+#define B_PARTNER_MONS_MARKED_SEEN      FALSE      // If TRUE, if your double battle partner sends out a Pokémon you haven't encountered yet, it will be marked as SEEN in your Pokédex.
 
 #define NUM_BEEPS_GEN_LATEST            4                    // Loops 4 times
 #define NUM_BEEPS_GEN_3                 -1                   // Loops infinitely

include/pokemon.h

@@ -849,6 +849,7 @@ u8 GetOpposingLinkMultiBattlerId(bool8 rightSide, u8 multiplayerId);
 u16 FacilityClassToPicIndex(u16 facilityClass);
 u16 PlayerGenderToFrontTrainerPicId(u8 playerGender);
 void HandleSetPokedexFlag(enum NationalDexOrder nationalNum, u8 caseId, u32 personality);
+void HandleSetPokedexFlagFromMon(struct Pokemon *mon, u32 caseId);
 bool8 HasTwoFramesAnimation(u16 species);
 struct MonSpritesGfxManager *CreateMonSpritesGfxManager(u8 managerId, u8 mode);
 void DestroyMonSpritesGfxManager(u8 managerId);