perf: Use Span CopyTo instead of Array CopyTo for better performance

[Youssef1313]

Benchmark:

    private static object UnsetValue = new();

    private static object[] _unsetStack = new object[10] { UnsetValue, UnsetValue, UnsetValue, UnsetValue, UnsetValue, UnsetValue, UnsetValue, UnsetValue, UnsetValue, UnsetValue };

    [Benchmark(Baseline = true)]
    public void ArrayCopy()
    {
        var arr = new object[10];
        Array.Copy(_unsetStack, arr, 10);
    }

    [Benchmark]
    public void SpanCopyToSpan()
    {
        var arr = new object[10];
        MemoryMarshal.CreateSpan(ref MemoryMarshal.GetArrayDataReference(_unsetStack), 10).CopyTo(MemoryMarshal.CreateSpan(ref MemoryMarshal.GetArrayDataReference(arr), 10));
    }

    [Benchmark]
    public void ArrayFill()
    {
        var arr = new object[10];
        Array.Fill(arr, UnsetValue);
    }

Outcome:

Method	Mean	Error	StdDev	Ratio	RatioSD	Gen 0	Gen 1	Gen 2	Allocated
ArrayCopy	14.60 ns	0.115 ns	0.096 ns	1.00	0.00	0.0497	-	-	104 B
SpanCopyToSpan	10.68 ns	0.071 ns	0.063 ns	0.73	0.00	0.0497	-	-	104 B
ArrayFill	30.13 ns	0.355 ns	0.332 ns	2.06	0.02	0.0497	-	-	104 B