Can create dimensionless Unitful vectors, but not ranges

Hi,

I'm trying to create vectors and ranges the elements of which are Unitful Quantities, but which have no units. That is, they are recognized as containing dimensionless Quantities.

I came across a surprising (to me) difference between vectors and ranges.

First note that

nounits = convert(Quantity{typeof(1),NoDims,Unitful.FreeUnits{(),NoDims,nothing}}, 1)

is a value equal to 1 that has no units. It is different from 1 itself:

1::Int64
>> 1

nounits::Quantity{Int64, NoDims, Unitful.FreeUnits{(), NoDims, nothing}}
>> 1

1::Quantity{Int64, NoDims, Unitful.FreeUnits{(), NoDims, nothing}}
>> ERROR

I can create a vector containing nondimensional Unitful Quantities

convert.(Quantity{Int64, NoDims, Unitful.FreeUnits{(), NoDims, nothing}}, collect(1:10))
>>10-element Vector{Quantity{Int64, NoDims, Unitful.FreeUnits{(), NoDims, nothing}}}:

and I can create a range containing dimensional Unitful Quantities

typeof(1*u"m":1*u"m":10*u"m")
>> StepRange{Quantity{Int64, 𝐋, Unitful.FreeUnits{(m,), 𝐋, nothing}}, Quantity{Int64, 𝐋, Unitful.FreeUnits{(m,), 𝐋, nothing}}}

typeof((1:10) .* u"m")
>> StepRange{Quantity{Int64, 𝐋, Unitful.FreeUnits{(m,), 𝐋, nothing}}, Quantity{Int64, 𝐋, Unitful.FreeUnits{(m,), 𝐋, nothing}}}

but I can't create a range containing nondimensional Unitful Quantities

typeof((1:10) .* nounits)
>> StepRangeLen{Int64, Int64, Int64, Int64}

typeof(nounits:nounits:10*nounits)
>> StepRange{Int64, Int64}

It would be good if it were possible to create non-dimensional Unitful ranges. This way, both dimensional and nondimensional vectors and ranges could be treated as containing Unitful Quantities.

Start by reproducing the dimensionless Quantity and range examples from the issue in Julia, then trace the range construction behavior for nounits and Unitful quantities. Done means nondimensional Unitful ranges preserve their Quantity element type, consistently with dimensional Unitful ranges.

Written by the indexing model from the issue text.