Updates dynamic pricing in `add_electricity`

[trevorb1]

Closes #235 #232

Changes proposed in this Pull Request

In this PR I update how dynamic fuel pricing is extracted and applied. Specifically:

• [x] Update EIA module to return pivoted data
• [x] Replace update_marginal_costs(...) with apply_dynamic_pricing(...) which applies dynamic pricing to one geography (state, ba, reeds zone) at a time.
• [x] Update the call of apply_dynamic_pricing(...) to raise an error if no EIA API is given
• [x] Update build_fuel_prices.py to return separate fuel files for different geographies. While this creates a little more clutter in the file tree, is greatly simplifies data processing imo.
• [x] Remove any legacy code from retrieve_cost_data.py that has been replaced by the eia module.

Checklist

• [x] I tested my contribution locally and it seems to work fine.
• [x] Code and workflow changes are sufficiently documented.
• [x] Changed dependencies are added to envs/environment.yaml.
• [x] Changes in configuration options are added in all of config.default.yaml.
• [x] Changes in configuration options are also documented in doc/configtables/*.csv.

[trevorb1]

A couple notes on the implementation:

• If dynamic_fuel_price is set to false, no fuel files are written out to the resources/{interconnect} folder
• If dynamic_fuel_price is set to true, and no API key is provided, an error is raised that is human readable (albiet, a little way into the workflow. but at least the error is clear)
  • AssertionError: Must provide EIA API key for dynamic fuel pricing
  • A note on this, we can still bring in caiso data, but this will not allow it. We should move that to its own issue tho, as this PR is getting a little big.
• If dynamic_fuel_price is set to true, and a API key is provided, fuel costs are written out at a per carrier and per geography level. Again, the motivation for this is while it results in a few more files, it makes the data processing easier.

[trevorb1]

@ktehranchi, I tagged you as a reviewer, but I dont think a formal review is really required. Just since you did the original implementation of dynamic prices, wanted to give you a chance to give thoughts if you had any before merging.

Functionality remains the same, but (I think) this implementation allows us to slot in new dynamic fuel pricing much easier

[trevorb1]

Im gonna go ahead and merge this so I can continue with PR #249. If you have any concerns, please feel free to revert @ktehranchi! :)