Validate short_names of the dataChoices.js

[NealHumphrey]

Our url encoding now uses the short_name property to encode data in the urls. We should add a validation step that raises an error if there are any duplicated short_names, to make sure that future developers do not break the encoding accidentally when adding new dataChoices and filters. Also be sure to include in the list any hardcoded url elements that are used elsewhere (ie. the codes for the sidebar and active project).

To protect against accidentally adding additional url codes that are not in dataChoices, we could also create a routine in the url encoding that makes sure that all encoded urls are in an approved master-list of codes. This would be created from the dataChoices list plus manually added ones that are used elsewhere. The effect of this requirement would be that if a coder adds a new short code that is manually hardcoded somewhere in the code, the encoding would fail when they test it until they added it also to the master list.

This is a post-launch enhancement.