Allow more than two timesteps

[vgeorge]

The summary returned at /scenarios route do not include years in key names, instead, it uses popConnectedBaseYear, popConnectedIntermediateYear and popConnectedFinalYear:

data-service/app/index.js

Lines 447 to 449 in a66be2b

	popConnectedBaseYear: {},
	popConnectedIntermediateYear: {},
	popConnectedFinalYear: {},

This doesn't affect the data stored, as it was ingested with year in their property names:

data-service/cli/scenarios.js

Lines 210 to 216 in a66be2b

	entry.summary[`Pop${baseYear}`] = nanParser(record[`Pop${baseYear}`]);
	entry.summary[`PopConnected${baseYear}`] = nanParser(
	record[`ElecPopCalib`]
	);
	entry.summary[`ElecCode${baseYear}`] = elecCodeParser(
	record[`FinalElecCode${baseYear}`]
	);

This is not an ideal implementation because there will be no way to represent a model with more than two time steps and the data service should account for that.

The files affected by these keys at the Explorer are:

• Charts.js
• Download.js