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

Thanks @DuBearte.

assets/locales/fr.json

@@ -487,6 +487,7 @@
   "cmd.sketch_fit_curves_to_section": "Ajuster des courbes à la section du maillage",
   "cmd.sketch_glyphs": "Symboles de contraintes",
   "cmd.sketch_include_3d": "Inclure une géométrie 3D",
+  "cmd.sketch_infinite": "Ligne infinie",
   "cmd.sketch_insert_dxf": "Insérer un DXF",
   "cmd.sketch_insert_svg": "Insérer un SVG",
   "cmd.sketch_inspect": "Inspecter l'esquisse",
@@ -979,6 +980,7 @@
   "ui.homeView": "Vue d'accueil",
   "ui.horizontal_vertical": "Horizontale/Verticale",
   "ui.import_ellipsis": "Importer…",
+  "ui.infinite": "Infinie",
   "ui.insert": "Insérer",
   "ui.inspect": "Inspecter",
   "ui.intersect": "Intersection",