Basic data assimilation module

[JaroCamphuijsen]

Resolves #82

Adds a new module, similar to the ERA5 module that can take any local data file (only supports netcdf format for now) and expose it as a model interface to the user. This enables easy data assimilation and forcing of the models.

• Implementation
• Settle on the naming
• Add requirements to setup
• Add tests
• Add documentation

[JaroCamphuijsen]

There is a problem of terminology here: for the MOSAIC project, it would be most logical to call this interface "Forcing", but in other domains that not used a lot. Also, the use of having a dataset being exposed as if it were a model can be used for other things than input forcing. For now I settled with calling the interface "Data" but I suppose that word is a bit overloaded already and might lead to problems in practical use. @goord @esclapez any ideas?

[goord]

Hi Jaro, 'forcing' is indeed not a good name for this 'modelwrapper', forcing is usually reserved for external source terms in the PDE's of some other model. So I would expect 'forcing' to be a very generic part of the omuse model interface, such as its 'grid' or 'time evolution'.

So how about "ModelWrapper'?

[JaroCamphuijsen]

ModelWrapper to me sounds too generic as almost every interface in OMUSE is a modelwrapper (they wrap around models). The unique thing about this interface is that it is about data. So "DataWrapper" would maybe be better. But it still doesn't really touch upon what it should do. Any other suggestions? Perhaps "ExternalData"?

[esclapez]

I think "ExternalData" or "ImportedData" is a name I would relate to what this does if I came across it.