Added foundation for 1.6 composite schedule testing

[folkengine]

Describe your changes

This PR establishes a way to test the creation of the Composite Schedule in a way that attempts to minimize the creation and combination of multiple Profiles using the OCPP 1.6 code as a foundation.

It includes:

1. A mechanism to easily deserialize Profiles from their actual JSON. This makes the creation of complex combinations of Profiles to test out different data textures much simpler.
2. Methods to dump out ChargingProfile and EnhancedChargingSchedule into JSON for easier debugging and visualization.
3. An initial unit test that combines two profiles in order to create an EnhancedChargingSchedule with two ChargingSchedulePeriods.

Issue ticket number and link

Checklist before requesting a review

• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• If OCPP 2.0.1: I have updated the OCPP 2.0.1 status document
• I read the contribution documentation and made sure that my changes meet its requirements

[christopher-davis-afs]

Re: tests, the Everest folks prefer snake_case for function names (but not test names)