Move dimension loading into CFDim.jl package

[felixcremer]

We discussed in Jena, that we would like to merge the loading of dimensions and the assignment of the correct dimension types between NetCDF and Zarr and also between Rasters and YAXArrays.
The idea was to move the according code to a new package CFDim.jl which could then be used from Rasters and YAXArrays.

What is the code that should be moved?

[rafaqz]

The problem is its pretty well bound to CommonDataModel and ArchGDAL, and I don't have the bandwith to separate it out.