Refactor `plot_validation_production.py` to use EIA930 data from PUDL

Feature Request

Catalyst Coop is currently in the midst of adding EIA930 data to PUDL.

They just produced their first nightly build that includes (relatively unprocessed) hourly EIA-930 balancing authority operations data, including the following 4 tables:

• core_eia930__hourly_interchange
• core_eia930__hourly_net_generation_by_energy_source
• core_eia930__hourly_operations
• core_eia930__hourly_subregion_demand

Docs are here, notebook poking at the data here.

Once the tables graduate to out_eia930_*, meaning they have been fully cleaned up and are production ready, we'll need to refactor build_demand to pull EIA930 data from PUDL.

Suggested Solution

• Identify which PUDL tables / columns we need
• Check in with Zane from Catalyst about when out versions of the data will be out
• Refactor workflow/scripts/plot_validation_production.py to query tables for data
• Update Snakefile to make plot_validation_production task depend on forthcoming retrieve_pudl task (#311)

Start with workflow/scripts/plot_validation_production.py and review the EIA930 tables and documentation linked in the issue to identify the needed tables and columns. Check the status of the out_eia930_* data with Catalyst and review the forthcoming retrieve_pudl task in #311. Update Snakefile dependencies and confirm plot_validation_production uses production-ready PUDL data.