feat: Add player state preconditions

src/Lavalink4NET/Players/Preconditions/PlayerPrecondition.cs

@@ -31,4 +31,10 @@ public static IPlayerPrecondition All(ImmutableArray<IPlayerPrecondition> precon
 
     public static IPlayerPrecondition All(params IPlayerPrecondition[] preconditions)
         => new AggregateAllPrecondition(preconditions.ToImmutableArray());
+
+    public static IPlayerPrecondition Status(ImmutableArray<PlayerState> states)
+        => new PlayerStatePrecondition(states);
+
+    public static IPlayerPrecondition Status(params PlayerState[] states)
+        => new PlayerStatePrecondition(states.ToImmutableArray());
 }

src/Lavalink4NET/Players/Preconditions/PlayerStatePrecondition.cs

@@ -0,0 +1,17 @@
+namespace Lavalink4NET.Players.Preconditions;
+
+using System;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+
+internal sealed record class PlayerStatePrecondition(ImmutableArray<PlayerState> AllowedStates) : IPlayerPrecondition
+{
+    public ValueTask<bool> CheckAsync(ILavalinkPlayer player, CancellationToken cancellationToken = default)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        ArgumentNullException.ThrowIfNull(player);
+
+        return new ValueTask<bool>(AllowedStates.Contains(player.State));
+    }
+}

src/Lavalink4NET/Players/Preconditions/SimplePrecondition.cs

@@ -13,4 +13,4 @@ public ValueTask<bool> CheckAsync(ILavalinkPlayer player, CancellationToken canc
 
         return new ValueTask<bool>(player.State == State);
     }
-}
+}