Move non-jellyfin extensions to separate project

src/Jellyfin.Extensions/ShuffleExtensions.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+
+namespace Jellyfin.Extensions
+{
+    /// <summary>
+    /// Provides <c>Shuffle</c> extensions methods for <see cref="IList{T}" />.
+    /// </summary>
+    public static class ShuffleExtensions
+    {
+        private static readonly Random _rng = new Random();
+
+        /// <summary>
+        /// Shuffles the items in a list.
+        /// </summary>
+        /// <param name="list">The list that should get shuffled.</param>
+        /// <typeparam name="T">The type.</typeparam>
+        public static void Shuffle<T>(this IList<T> list)
+        {
+            list.Shuffle(_rng);
+        }
+
+        /// <summary>
+        /// Shuffles the items in a list.
+        /// </summary>
+        /// <param name="list">The list that should get shuffled.</param>
+        /// <param name="rng">The random number generator to use.</param>
+        /// <typeparam name="T">The type.</typeparam>
+        public static void Shuffle<T>(this IList<T> list, Random rng)
+        {
+            int n = list.Count;
+            while (n > 1)
+            {
+                int k = rng.Next(n--);
+                T value = list[k];
+                list[k] = list[n];
+                list[n] = value;
+            }
+        }
+    }
+}