Ensure new Data Point identifiers are 14 chars long

When a data point identifier/UID is generated by com.gallatinsystems.surveyal.domain.SurveyedLocale.generateBase32Uuid(), there is a risk of it being truncated, ending up as abcd-efgh-jkm (or even shorter). This occurs if the number has one or more leading zeroes when converted to base-32, so stastically it happened for 1/32 identifiers.