Ensure area names are read as strings in RTS-GMLC, even if numeric

[darrylmelander]

Fixes # .

When parsing RTS-GMLC csv files, if area names were numeric (such as an area named "1"), then some places in the RTS-GMLC parser read the area names as strings and other places read the names as numbers. This caused time series data for areas to not be associated with the correct area.

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