[Feature Contribution]: Add extended forecast horizons for the ElectricityMaps API

[unitrium]

What happened?

The ElectricityMaps API now supports up to 72 hours forecasts in the future. This is enabled by passing the optional argument horizonHours to an API query.
https://portal.electricitymaps.com/docs/api#carbon-intensity-forecast

The idea would be to add the possibility to pass this optional argument to API calls to the ElectricityMaps API and get longer forecasts.

cc @jbdietrich @lav-julien

Code of Conduct

• I agree to follow this project's Code of Conduct

Feature Commitment

• I commit to contributing this feature as a PR and working with the GSF to merge this feature into the Carbon Aware SDK.