General enhancements for standardization

[knoiva-indecon]

General enhancements for standardization and efficiency (coordinate with FrEDI repo Issue #180). In order of staging:

1. Scenarios. Add steps to configuration workflow to add formatted scenarios to configuration data. Move any scenarios (e.g., population, GDP) to "inst/extdata/scenario" directory. Remove scenarios from "FrEDI_config.xlsx" file and add steps to read in the scenarios and process them (to be saved in "data" and "inst/extdata/scenarios" directories of FrEDI package. Make sure to also include the GDP scenario (see Issue Default scenarios FrEDI#85). Make sure steps to create default scenarios are derived from these scenarios.
2. Scaled Impacts. Remove scaled impacts workflow from FrEDI_config.xlsx, and remove regional steps from FrEDI configuration workflow (if not already done).
3. maxYear and npdYear. In "FrEDI_config.R", change maxYear = 300 to maxYear = 2100, and set npdYear = 300. Make sure configuration steps configure default data out to npdYear instead of maxYear.
4. Region columns. Consider adding regCols to specify the names of the region columns (e.g., regCols = c("region", "state", "postal")). This would be for standardization with the methane module, which will have a global value. Alternatively, can keep the save region column names. Alternatively, if at the global level, regioncould be associated with continent,statecould be associated with country, andpostalset to country-level postal code abbreviation -- or, if there is no country-level postal code available,postal` could be set to "NA" for internal calculations and then dropped before returning results.

Additional standardizations may be added to this list.

[knoiva-indecon]

Addressed with Issue #101