Apply input data needs names to work with use_attributes

Hi @aho!

I want to check how well ClimProjDiags fits with Compute, as ClimProjDiags is following the approach of working in arrays of any number of dimensions with named dimensions.

To do it, I would develop examples for each of them. The first one has been DTRRef, which inputs are two variables maximum and minimum temperature, and it also require the dates to do the calculation. So, the example will require two calls for Start() and the parameter use_attributes.

When running Compute, a warning appears indicating that the names of the use of attributes didn't match with the names of the input data:

5: In multiApply::Apply(data, target_dims = attr(step_fun, "TargetDims"),  :
  Parameter 'use_attributes' provided with names, but no names provided for 'data'. All names will be disregarded.

However, I was providing the same names. I think that the parameter 'cube_headers' had the names when function ByChunks() starts running, but later they aren't passed to 'data' in the call of Apply.

The solution I propose in this branch solve the problem in the example I did. See the exemple in the file /esarchive/scratch/nperez/git/Flor/ClimProjDiags_Tests/DTRRef_Ex_Start.R

Could you consider this fix or improving it?

Thanks!

Núria