Add French carbon intensity provider

[mrchrisadams]

I found a cool project called Tracarbon the other day.

They do a lot of what this project does, but I discoered that they use a data feed from what appears to a French grid operator for free, hourly, average carbon intensity data.

https://www.rte-france.com/eco2mix

Here's the code we'd need to implement in Golang to provide the numbers in an exporter for France

https://github.com/fvaleye/tracarbon/blob/main/tracarbon/locations/country.py#L113

And here's an example of the data returned in a request:
https://odre.opendatasoft.com/api/records/1.0/search/?dataset=eco2mix-national-tr

I haven't looked into the geographical or temporal resolution for this, nor the licensing, but it looks to be around hourly.

[rossf7]

This is a great find and integrating with the API doesn't look too hard.

Once the API changes in #44 are done I think we could add this provider and document the steps involved.

This would make it easier for the community to contribute more providers.

[mrchrisadams]

This appears to be national level info, updating every 15 minutes.

Here's an example API call:

https://odre.opendatasoft.com/api/records/1.0/search/?dataset=eco2mix-national-tr&q=&rows=1&facet=taux_co2&facet=date_heure&refine.date=2022-09-25&refine.heure=18:30

Broken down, and in pseudo code that request is largely

https://odre.opendatasoft.com/api/records/1.0/search/ # our API path
dataset=eco2mix-national-t    # use this dataset
rows=1                        # just give us one row for the next 30mins
facet=taux_co2                # we want taux_co2 (I'm not sure what the french is here - presumably total CO2?)
facet=date_heure              # filter by time
refine.date=2022-09-25        # we need to pass the date we are querying for
refine.heure=18:30            # we also need to pass the hour and minute.

You need to send data in UTC time.

Presumably, we could use the Carbon Intensity UK provider as a reference point, as that is similarly tied to a specific country / location

https://github.com/thegreenwebfoundation/grid-intensity-go/blob/main/pkg/provider/carbon_intensity_uk.go