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

[jpvelez]

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)