Handle duplicate contest names gracefully

[sfsinger19103]

The current system pulls contest names from a CVR and can't distinguish two contests in a single county with identical names but different contest ids. Contest ids are not part of the CVR export. If multiple contests have the same name (ignoring any trailing white space) but accept different numbers of votes, the CVR file is reported as invalid.

Using ENR exports received to date based on LAT testing with the 2017 election definitions for Colorado, we have detected duplicates in a few counties, because the ENR exports include not just contest names but also contest ids (unique for each contest within the county).

For Nov 2017, we will use a workaround, to edit the CVR files, and ensure that contest names in CVRs used for audit will be unique within counties.