Sketch: infinite construction lines (#1359) (#1547)

Thanks @DuBearte.

assets/locales/ja.json

@@ -507,6 +507,7 @@
   "cmd.sketch_fit_curves_to_section": "メッシュ断面に曲線をフィット",
   "cmd.sketch_glyphs": "拘束記号",
   "cmd.sketch_include_3d": "3D ジオメトリを含める",
+  "cmd.sketch_infinite": "無限線",
   "cmd.sketch_insert_dxf": "DXF を挿入",
   "cmd.sketch_insert_svg": "SVG を挿入",
   "cmd.sketch_inspect": "スケッチを検査",
@@ -1139,6 +1140,7 @@
   "ui.homeView": "ホームビュー",
   "ui.horizontal_vertical": "水平/垂直",
   "ui.import_ellipsis": "インポート…",
+  "ui.infinite": "無限",
   "ui.insert": "挿入",
   "ui.inspect": "検査",
   "ui.intersect": "交差",