Add step to set simulation engine when creating a scenario

[rouille]

Purpose

Add a feature allowing the user to set the simulation engine when creating a scenario. See issue #139 where most of the steps needed to implement this feature have been tested.

What is the code doing?

• add the engine key to the _scenario_info attribute (type: dict) of the Create object.
• add the engine attribute to the _Builder object with REISE (type: str) as default value.
• update the update_scenario_info method in the Create object.
• write the set_engine method in the _Builder object (limited to only REISE for now).
• use scripts call.py and extract_data.py associated to engine set by user in the Execute object.
  The engine will be written in a new column right after the interval column.

Where to look

Two modules have been modied:

• powersimdata.scenario.create
• powersimdata.scenario.execute

Time estimate

30 minutes

Note

This PR can only be merged once a new column has been added to the ScenarioList.csv for the existing scenarios. Also, a companion PR that takes care of the insertion of the runtime and infesibilities in ScenarioList.csv handled, respectively, by the call.py and extract_data.py scripts will be created in REISE.