Currently the range template is a child of the barracks template, which is odd; the elephant stable, dog kennel, and workshop all inherit from the military template, not from the barracks template.
- moves template_structure_military_barracks_range.xml to template_structure_military_range.xml
- updates all its children accordingly
- changes generic name to Practice Range (because it not only trains archers, but also slingers and javelinists)
- footprint, rubble, obstruction, and visual actors are removed from civ specific templates, unless they differ from the generic template