Enumerable Product extension method

[snowfrogdev]

This extension method is similar to the Sum method, except that it multiplies the items in the IEnumerable instead of adding them. I've implemented it for every type of number (int, long, float, double, decimal) and have tested it extensively.

Benchmarks show that the chosen implementation offers significant performance over other common alternatives.

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.22000
12th Gen Intel Core i9-12900K, 1 CPU, 24 logical and 16 physical cores
.NET Core SDK=6.0.400
  [Host]     : .NET Core 6.0.8 (CoreCLR 6.0.822.36306, CoreFX 6.0.822.36306), X64 RyuJIT
  DefaultJob : .NET Core 6.0.8 (CoreCLR 6.0.822.36306, CoreFX 6.0.822.36306), X64 RyuJIT

Method	N	Mean	Error	StdDev	Ratio	Gen 0	Gen 1	Gen 2	Allocated
ProductAggregate	1	12.285 ns	0.1644 ns	0.1538 ns	1.00	0.0020	-	-	32 B
ProductForEach	1	10.475 ns	0.0928 ns	0.0868 ns	0.85	0.0020	-	-	32 B
Product	1	3.064 ns	0.0372 ns	0.0348 ns	0.25	-	-	-	-
ProductAggregate	10	41.003 ns	0.2373 ns	0.1981 ns	1.00	0.0020	-	-	32 B
ProductForEach	10	33.809 ns	0.4208 ns	0.3514 ns	0.82	0.0020	-	-	32 B
Product	10	5.888 ns	0.0842 ns	0.0787 ns	0.14	-	-	-	-
ProductAggregate	100	364.044 ns	5.4466 ns	4.5481 ns	1.00	0.0019	-	-	32 B
ProductForEach	100	299.335 ns	2.4880 ns	2.3272 ns	0.82	0.0019	-	-	32 B
Product	100	47.687 ns	0.3365 ns	0.2983 ns	0.13	-	-	-	-
ProductAggregate	1000	3,242.624 ns	22.2032 ns	17.3348 ns	1.00	-	-	-	32 B
ProductForEach	1000	2,874.950 ns	24.9146 ns	22.0861 ns	0.89	-	-	-	32 B
Product	1000	750.601 ns	7.5546 ns	7.0666 ns	0.23	-	-	-	-