templatekw: expose color name in {namespaces} entries Templates make use of a "log.<namespace>" label. The <namespace> value here differs from the actual namespace name in that the namespace itself is plural but the label/color value is singular. Expose the color name to the templating layer so log.* labels can be emitted for {namespaces}. As part of this, we refactored the logic to eliminate a gnarly comprehension. We store color names in their own dict because the lookup can occur in tight loops and we shouldn't have to go to repo.names[ns] multiple times for every changeset.