Update ElectricityMapsDataSource.cs (Green-Software-Foundation#365)

Issue : 

I have tested a ElectricityMaps forecast scenario CLI: 
"emissions-forecasts -l westeurope -v"
will return server error 500.

Analysis:

public async Task<EmissionsForecast> GetCurrentCarbonIntensityForecastAsync(Location location) is causing the EM server to return 500. Reason is that the "." in geolocation.Latitude will be passed as "," 

Fix:

The following changes are fixing this bug.

Signed-off-by: Christian Binder <43334159+xcbinder@users.noreply.github.com>

src/CarbonAware.DataSources/CarbonAware.DataSources.ElectricityMaps/src/ElectricityMapsDataSource.cs

@@ -45,8 +45,8 @@ public async Task<EmissionsForecast> GetCurrentCarbonIntensityForecastAsync(Loca
     {
         ForecastedCarbonIntensityData forecast;
         var geolocation = await this._locationSource.ToGeopositionLocationAsync(location);
-        if (geolocation.Latitude != null && geolocation.Latitude != null)
-            forecast = await this._electricityMapsClient.GetForecastedCarbonIntensityAsync (geolocation.Latitude.ToString() ?? "", geolocation.Longitude.ToString() ?? "");
+        if (geolocation.Latitude != null && geolocation.Longitude != null)
+            forecast = await this._electricityMapsClient.GetForecastedCarbonIntensityAsync (geolocation.LatitudeAsCultureInvariantString(), geolocation.LongitudeAsCultureInvariantString());
         else
         {
             forecast = await this._electricityMapsClient.GetForecastedCarbonIntensityAsync (geolocation.Name ?? "");