Create all data and tables necessary for the model before the function

[abelsiqueira]

We can control and improve both the creation of the data/tables and the create_model function better if these concerns are separated.
This includes the "expression" data, e.g., data that informs the incoming and outgoing flow.
This includes clustering stuff (representative periods, timeframe, years, etc.)
Partition should also be created before the model, though we are missing the "scenario specification" data as a separate entity

• Clean up create_model. Create files and functions to make it look nicer
• Move dataframe updates to before create_model if possible. Mark places that are waiting for Define variable tables #884
• Sets can be created beforehand as well