Give solid.move the copy half of its Move/Copy label (#498)

solid.move takes copy: true to keep the source bodies and transform a new copy of each, with a Create Copy box in the Move dialog. Designs without it save and load exactly as before.

crates/ui-egui/src/locales/ja.json

@@ -69,6 +69,7 @@
   "ui.counterbore": "座ぐり",
   "ui.countersink": "皿もみ",
   "ui.create": "作成",
+  "ui.create_copy": "コピーを作成",
   "ui.create_sketch": "スケッチを作成",
   "ui.current": "現在",
   "ui.curvature": "曲率",