Refactor architecture to use Tables (DataFrames)

[abelsiqueira]

Description

Given the changes that are happening in the input (ref #289) and that happened in the model, it makes sense to use Tables to store most of data, instead of converting the data into other structures only to convert them back to dataframes in the model.

We should benchmark and evaluate the changes to make sure they are good ideas.

Sub issues

• Separate the reading and processing in the IO #544
• Return dataframes as the output format #115
• Change representative_periods to data frames
• Change base_periods to data frames
• Change constraints_partitions to data frames
• Change graph to a mix of Graph and data frames
• Use dataframes instead of dict for RP weight matrix #495
• Change construct_dataframes to use input data frames #611