Reusable TMs

[Bassoonian]

A quick and straightforward way to make TMs reusable by assigning them an importance value of 1. Any TM that does not have this importance value functions as expected. Item removal after teaching a move is no longer based on item ID but rather on importance now. A gen-based config has been added for easy toggling for now, but perhaps a plain TRUE/FALSE config would be more straightforward to use.

This PR does NOT include retaining PP of the older move when a new one is taught, as is the case in the official games. This mechanic would also affect the move relearner if it can be accessed from the party menu and should perhaps evaluate a different config.

Discord contact info

Jasper#5206

[LOuroboros]

This PR does NOT include retaining PP of the older move when a new one is taught

You could include it though. There kind of isn't a reason not to, it's quick and it'd save the trouble of having to submit it in a separate PR, not to mention it's obviously related to the action of making TMs reusable.
EDIT: Forgot to add that TMs only started to restore PP after Gen. 5 or 6 iirc, so providing the option to make TMs not restore PP would be in accorance to certain generations of mainline games.

In include/config/item.h

#define I_TMS_RESTORE_PP          TRUE  // If TRUE, TMs will teach a move at full PP.

In src/party_menu.c, I think modifying Task_PartyMenuReplaceMove like this would be good enough, and makes the function more readable too imo.

 static void Task_PartyMenuReplaceMove(u8 taskId)
 {
     struct Pokemon *mon = &gPlayerParty[gPartyMenu.slotId];
     u16 move = gPartyMenu.data1;
     u8 oldPP = GetMonData(mon, MON_DATA_PP1 + GetMoveSlotToReplace(), NULL);
 
     if (IsPartyMenuTextPrinterActive() != TRUE)
     {
         RemoveMonPPBonus(mon, GetMoveSlotToReplace());
         SetMonMoveSlot(mon, move, GetMoveSlotToReplace());
     #if I_TMS_RESTORE_PP == TRUE
         if (GetMonData(mon, MON_DATA_PP1 + GetMoveSlotToReplace(), NULL) > oldPP)
             SetMonData(mon, MON_DATA_PP1 + GetMoveSlotToReplace(), &oldPP);
     #endif
         Task_LearnedMove(taskId);
     }
 }

[Bassoonian]

Ready for re-review. Doesn't include the PP restoration thing because tasks and my lack of expertise in regards to them.