improve csv sort indices for unsummarized download

[jeffzyliu]

Description

Unsummarized download orders by globalID instead of year etc.. because we sort on Model.schema.indexes()[0][0]:

need to search for Model.schema.indexes()[one with 'year'][0] instead.

EDIT we already have this! getModelIndexes in utils. but it needs unique on the index, so it doesn't work unless we get like a weekNumber on it? but that doesn't make much sense. never mind.

Type of Issue

• New feature
• Bug fix
• Documentation update