Standardize NREL mappings

[trevorb1]

We use the NREL dataset in multiple places throughout the code base (such as in costs and capacity factor). We include a mapping dictionary to match our technology naming to NREL technology scenarios...

Canada-U.S.-ElecTrade/scripts/Costs.py

Lines 100 to 110 in c8af7e6

	technology = {
	'COA':['Coal', 'IGCCHighCF'] ,
	'COC':['Coal', 'CCS30HighCF'] ,
	'HYD':['Hydropower', 'NPD4'] ,
	'CCG': ['NaturalGas','CCHighCF'],
	'CTG': ['NaturalGas','CTHighCF'],
	'WND': ['LandbasedWind','LTRG4'],
	'SPV': ['UtilityPV','KansasCity'],
	'URN': ['Nuclear'],
	'BIO': ['Biopower','Dedicated'],
	}

We should create a solution where we specify this at a global level (such as the config.yaml file, but Im not sure it really belongs there), so they never become mismatched.

[trevorb1]

Oh I just saw we have constants in the functions.py file ! May want to move them to a constants.py file or something