Use lan/lot coordinates for mapping/coupling models

[JaroCamphuijsen]

Currently when using the bilinear_2D_remapper , (or any other mapper for that matter) to map a dataset (either from the ERA5 module or the Data module) to a model (in this case a Delft3DFM gtsm model), the lat/lon coordinates are not used to map one grid onto the other. For geospatial data and earth models this is unexpected/unwanted behavior as you would expect a grid with coordinates from -180 to 180 longitude to be mapped properly to a grid of 0 to 360 longitude.

This can be implemented either by:

• using a default reference point to which all grids are converted
• do the alignment during the coupling/mapping, which would require a different implementation of the various mappers in amuse (perhaps it could check whether a lon/lat coordinate exists?)
• or an additional layer in omuse
• having a different implementation and concept of the omuse grid object as opposed to the amuse grid object