Added new noise generation methods in `ParallelNoiseBenchmark`, including `Frac`, `Lerp`, and `GradientNoiseDirect`, and updated the `GradientNoise` method to utilize them. Changed constants to use `_LENGTH` for consistency.
Changed `Arena` and `DynamicArena` classes to use `uint` instead of `ulong` for size fields, improving memory usage. Updated memory allocation to use `NativeMemory` for better performance and safety.
Updated `UnsafeArray<T>` and `UnsafeList<T>` classes to replace `Marshal` methods with `NativeMemory`, enhancing performance and safety. Modified `Dispose` methods to use `NativeMemory.AlignedFree`.
Added `MemoryUtilities` class with new methods for memory management, including `MemClear`, `MemSet`, `MemCpy`, `SizeOf`, and `AlignOf`, utilizing `NativeMemory`.
Fixed minor cleanup in the `ObjectPool` class's `Dispose` method.
