Allow JSON load to set element IDs #87
Description
SimulationData saves each element's ID (my_id) when exporting to JSON. However, when it imports from JSON, it ignores the element ID because add_element() in https://github.com/NREL/SolTrace/blob/develop/coretrace/simulation_data/simulation_data.cpp fails if the element already has an ID assigned.
TODO: Determine best method for loading simulation data from JSON. Better to allow simulation data to reassign new ID's to elements, or directly load in the ID's saved in the file?