RecyclableArrayList.Contains fixed to not throw exception when the list is empty.

RecyclableArrayList tests sorted alphabetically, simplified & extended to use the test data & validate various combinations of item counts & block sizes.

Recyclable.Collections/RecyclableArrayList.cs

@@ -372,7 +372,7 @@ namespace Recyclable.Collections
 			_count = 0;
 		}
 
-		public bool Contains(T item) => _memoryBlock.Contains(item);
+		public bool Contains(T item) => Array.IndexOf(_memoryBlock, 0, _count) >= 0;
 
 		public void CopyTo(T[] array, int arrayIndex) => Array.Copy(_memoryBlock, 0, array, arrayIndex, _count);