Motivation: The sides are unstructured because they have a width. Either
we need a new setting unstructured_sides or make the whole domain
unstructured. Since nested domains will probably be unstructured too,
we choose the latter.

Specifically, datastore keys are now tupels of ('metadata', key) or ('maindata', key)

Lsce

See merge request !42

Devel

See merge request satinv/cif!162

WRF lateral boundaries have widths, which is not the case in other models implemented in CIF so far. To accomodate this, we overwrite the domain's default 'get_sides' function here.

Groups monitor

See merge request satinv/cif!161