Add benchmark method and improve Unsafe collections

Added a new benchmark method `For` in `ParallelNoiseBenchmark` to test gradient noise generation.
Added demonstration code for `UnsafeArray` in `Program.cs` with a custom `Test` struct.

Changed property accessors in `IUnsafeCollection<T>` to use `ref` returns for better memory efficiency.
Changed property accessors and indexers in `UnsafeArray<T>`, `UnsafeList<T>`, and `UnsafeQueue<T>` to return `ref` types.
Changed `TryDequeue` in `UnsafeQueue<T>` to return a default value instead of null.
Changed `Clear` and `Dispose` methods in `UnsafeQueue<T>` to reset size and offset.

Removed commented-out `BenchmarkRunner` code in `Program.cs`.

Misaki.HighPerformance.Unsafe/Collections/Contracts/IUnsafeCollection.cs

@@ -3,11 +3,17 @@
 public unsafe interface IUnsafeCollection<T> : IDisposable
     where T : unmanaged
 {
-    public T* Buffer { get; }
+    public T* Buffer
+    {
+        get;
+    }
 
-    public int Size { get; }
+    public int Size
+    {
+        get;
+    }
 
-    public T this[int index] { get; }
+    public ref T this[int index] { get; }
 
     public void Clear();
     public void ReAlloc(int newSize);