Call graphs from eesyplan methods

[paulapreuss]

Goal

• Save copy of datapackage to database to create enerysystem without having to build datapackage from scratch
• Call graphs directly from eesyplan methods instead of openplan code

Notes:

• Added datapackage field to Scenario instead of Simulation to not have to worry about if a simulation object already exists
• Added argument store_database_record to to_jsonified_datapackage method instead of calling again with n_timestamps=0 to only build the datapackage once and strip the timeseries instead of building twice (once for simulation and once for db)
• EnergySystem can be rebuilt from db datapackage after repopulating with Timeseries values
• WIP state: Sankey diagram now works like this (renders) but does not display the correct values yet (probably something is different in the logic of rebuilding the flows?)