note: this commit does not also update the alembic schema or remove
the original epacamd_eia table from the db.

…ssions_unit_id_epa with generator id. Also remove the replacement of empty plant_id_epa values with plant_id_eia to avoid confusion about which plants are reporting to EPA and which are not.

Also add boiler id to the bga table merge in augement_crosswalk_with_bga_eia860.

Noticed that there is an issue with some of the BGA relationships getting dropped during the subplant id creation, but I'm not sure how to fix this yet.

…e subplant_id table. Add code to merge the boiler_id back into the subplant_id table after the network x process because some boilers get dropped.

… fail in the emacamd_eia_subplant_ids function and add a convert_dtypes() function to the boiler_generator_assn_eia860_test table instead

…he metadata for the subplant_id table

…ut removing that table from the database

…Replace epacamd_eia validation test with epacamd_eia_subplant_id validation test