function to map/aggregate the regional electricity data to the exiobase classification

This function relies on the concordances between the ENTSO electricity data and EXIOBASE classification as well as the regional mapping between the two datasets (although the latter should be relatively straightforward).

The ENTSO regional electricity data needs to be mapped/aggregated to the exiobase regions. Secondly the electricity production processes need to be mapped to the EXIOBASE classification.

output: a exiobase-region X exiobase-electricity-source matrix* with the updated electricity mixes.

*The format does not need to be a matrix, but can be different (e.g. list of dictionaries, pandas dataframe, etc), in coordination with the function that injects the data into the exiobase SUTs.