merge equivalent RFF resources #3857
Description
As mentioned in #3148 , these are the same resource:
- utility: https://datacommons.rff.org/browser/dc/05gsw4m93mz6 = https://datacommons.rff.org/browser/eia/u/13407
- power plant: https://datacommons.rff.org/browser/dc/3lwrcytjq2k09 = https://datacommons.rff.org/browser/eia/pp/2322
However, they have distinct dcid and there's no relation between them.
Please merge these resources (the dc/ resources seem poorer than the eia/ resources), including attributes and incoming/outgoing links.