Economic evaluation from secondary regulation

Add functionalities for estimating revenue from market participation

Revenue scheme: pay-for-performance (PJM)

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Suggested workflow:

1. Create a "function" version of main.py to allow for multiple runs
2. Get the corresponding price timeseries from PJM website
3. Create class for revenue calculation
4. Include simulation output statistics (KPIs) in the simulation output object
5. Create module for multiple runs
6. Create class for runs comparison and statistics

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Tip: Tick boxes when ready