base_fuel calculations if all tech_specs bases are False

[babakkhavari]

This needs to calculate a base_fuel technology, with the weighted average parameters of all technologies.

[camiloramirezgo]

This needs to be disaggregated by urban/rural

[camiloramirezgo]

We need to move this information from the Prep_files to the Technical_specs:

Technology	Share	Data type
Urb_Cook_Biomass	0.07089	float
Urb_Cook_Charcoal	0.153005	float
Urb_Cook_Coal	0	float
Urb_Cook_Electricity	0.03696	float
Urb_Cook_Gas	0.68971	float
Urb_Cook_Kerosene	0.02041	float
Rur_Cook_Biomass	0.07089	float
Rur_Cook_Charcoal	0.153005	float
Rur_Cook_Coal	0	float
Rur_Cook_Electricity	0.03696	float
Rur_Cook_Gas	0.68971	float
Rur_Cook_Kerosene	0.02041	float

This will make it easier to loop through all technologies and calculate the weighted average of the parameters.

[camiloramirezgo]

We would need the following properties from all technologies, which will then be used to calculate the weighted averages:

['carbon', 'pm25', 'total_time_yr']

If the carbon or total_time_yr have not been calculated fora technology, then the function should call .carb() and .total_time() for the technology.