Sphere 2D Data: Migrate to FileDict-based storage for file input/output
SWEET has a flexible dictionary-based storage class. This allows to store arbitrary data into a class which can then again be stored or read to/from the file system. There's also a counterpart in Python for this. All File I/O should be hence ported to this new interface.
This issue is for the Sphere2D Data version of this.
More information
E.g., for DataSpectral update this code to use the Dictionary for writing files https://gitlab.inria.fr/sweet/sweet/-/blob/main/src/include/sweet/Data/Sphere2D/DataSpectral.cpp#L1334 and also the function for loading such files.
Same for DataGrid.
Same for the Sphere2DComplex variant.
All Data input/output should only be accomplished with the Dict class.
These changes also have to be done on the Python side, e.g., in https://gitlab.inria.fr/sweet/sweet/-/blob/main/mule_local/python/postprocessing/Sphere2DDataSpectral.py Changing to the FileDict https://gitlab.inria.fr/sweet/sweet/-/blob/main/mule_local/python/SWEETFileDict.py would significantly reduce the code complexity.