piracy on `Base.sum` and `Base.prod`

[adienes]

in these methods

Measurements.jl/src/math.jl

Line 779 in 86adc26

Base.sum(a::AbstractArray{<:Measurement}) = result(sum(value.(a)), ones(length(a)), a)

Measurements.jl/src/math.jl

Lines 785 to 790 in 86adc26

	function Base.prod(a::AbstractArray{<:Measurement})
	x = value.(a)
	return result(prod(x),
	[prod(deleteat!(copy(x), i)) for i in eachindex(x)],
	a)
	end

I see this was done as an optimization, but it feels like it might be more appropriate as its own function rather than Base.sum to avoid all the known issues with piracy (particularly method invalidations contributing to load times & recompilation). this design also means there is a discrepancy between e.g. Base.sum(x) and Base.sum(x; dims=:)