Extract minimum trainer information requirements

If one wanted to extend ConvertToPKM to other IEncounterables, this
would be the provided obj containing the receiver's info

allows pkm gen without a savefile, which is nice?

PKHeX.Core/Legality/Structures/ITrainerInfo.cs

@@ -0,0 +1,21 @@
+namespace PKHeX.Core
+{
+    /// <summary>
+    /// Minimal Trainer Information necessary for generating a <see cref="PKM"/>.
+    /// </summary>
+    public interface ITrainerInfo
+    {
+        string OT { get; }
+        ushort TID { get; }
+        ushort SID { get; }
+        int Gender { get; }
+        int Game { get; }
+        int Language { get; }
+
+        int Country { get; }
+        int SubRegion { get; }
+        int ConsoleRegion { get; }
+
+        int Generation { get; }
+    }
+}

PKHeX.Core/MysteryGifts/MysteryGift.cs

@@ -80,7 +80,7 @@ public static MysteryGift GetMysteryGift(byte[] data)
         public string Extension => GetType().Name.ToLower();
         public string FileName => $"{CardHeader}.{Extension}";
         public byte[] Data { get; set; }
-        public abstract PKM ConvertToPKM(SaveFile SAV);
+        public abstract PKM ConvertToPKM(ITrainerInfo sav);
         public abstract int Format { get; }
 
         /// <summary>

PKHeX.Core/MysteryGifts/PGF.cs

@@ -149,7 +149,7 @@ public override int CardID
         public override bool IsItem { get => CardType == 2; set { if (value) CardType = 2; } }
         public bool IsPower { get => CardType == 3; set { if (value) CardType = 3; } }
 
-        public override PKM ConvertToPKM(SaveFile SAV)
+        public override PKM ConvertToPKM(ITrainerInfo SAV)
         {
             if (!IsPokémon)
                 return null;

PKHeX.Core/MysteryGifts/PGT.cs

@@ -112,7 +112,7 @@ public bool GiftEquals(PGT pgt)
             return true;
         }
 
-        public override PKM ConvertToPKM(SaveFile SAV)
+        public override PKM ConvertToPKM(ITrainerInfo SAV)
         {
             return Gift.ConvertToPKM(SAV);
         }
@@ -233,7 +233,7 @@ private void EncryptPK()
         public override int Location { get => PK.Met_Location; set => PK.Met_Location = value; }
         public override int EggLocation { get => PK.Egg_Location; set => PK.Egg_Location = value; }
 
-        public override PKM ConvertToPKM(SaveFile SAV)
+        public override PKM ConvertToPKM(ITrainerInfo SAV)
         {
             if (!IsPokémon)
                 return null;

PKHeX.Core/MysteryGifts/WC3.cs

@@ -60,9 +60,8 @@ public int Met_Level
             set => _metLevel = value;
         }
 
-        public override PKM ConvertToPKM(SaveFile SAV)
+        public override PKM ConvertToPKM(ITrainerInfo SAV)
         {
-            var pi = SAV.Personal.GetFormeEntry(Species, 0);
             PK3 pk = new PK3
             {
                 Species = Species,
@@ -82,6 +81,7 @@ public override PKM ConvertToPKM(SaveFile SAV)
 
                 FatefulEncounter = Fateful,
             };
+            var pi = pk.PersonalInfo;
 
             if (Version == 0)
             {

PKHeX.Core/MysteryGifts/WC6.cs

@@ -278,7 +278,7 @@ public override int[] RelearnMoves
             }
         }
 
-        public override PKM ConvertToPKM(SaveFile SAV)
+        public override PKM ConvertToPKM(ITrainerInfo SAV)
         {
             if (!IsPokémon)
                 return null;

PKHeX.Core/MysteryGifts/WC7.cs

@@ -302,7 +302,7 @@ public override int[] RelearnMoves
             }
         }
 
-        public override PKM ConvertToPKM(SaveFile SAV)
+        public override PKM ConvertToPKM(ITrainerInfo SAV)
         {
             if (!IsPokémon)
                 return null;

PKHeX.Core/Saves/SaveFile.cs

@@ -8,7 +8,7 @@ namespace PKHeX.Core
     /// <summary>
     /// Base Class for Save Files
     /// </summary>
-    public abstract class SaveFile
+    public abstract class SaveFile : ITrainerInfo
     {
         public static bool SetUpdateDex { protected get; set; } = true;
         public static bool SetUpdatePKM { protected get; set; } = true;