CenterCell should be the default staggering in CommonSpaces

[Sbozzolo]

I think that assuming a center staggering for CommonSpaces is a reasonable default, and it would help creating spaces easier.
For instance, the example

using ClimaCore.CommonSpaces
space = ColumnSpace(;
    z_elem = 10,
    z_min = 0,
    z_max = 10,
    staggering = Grids.CellCenter()
)

does not work because Grids is not imported. Importing Grids seems a little excessive when the module is only needed to set up the space.

Also, I think it would be good to have a function to go from center to face space and viceversa.