Move all battle state from IPokemon to an ephemeral IBattlePokemon wrapper

PkmnLib.Dynamic/Models/BattleResult.cs

@@ -30,4 +30,11 @@ public record struct BattleResult
     /// The side that won the battle. If null, no side has won.
     /// </summary>
     public byte? WinningSide { get; }
+
+    /// <summary>
+    /// The Pokémon that were captured during the battle. These are the underlying Pokémon, so they remain
+    /// valid after the battle has been disposed. This is set for both conclusive and inconclusive results, as
+    /// captures complete the moment they happen.
+    /// </summary>
+    public IReadOnlyList<IPokemon> CapturedPokemon { get; init; } = [];
 }