Revert #1682 (three-axis milling) (#1715)

Thanks @bherbruck.

assets/locales/en.json

@@ -305,22 +305,6 @@
   "cmd.browser_rename_group": "Rename Group",
   "cmd.browser_ungroup": "Ungroup",
   "cmd.browser_visibility": "Show/Hide",
-  "cmd.cam_boundary_from_profile": "Use Sketch Profile",
-  "cmd.cam_delete": "Delete Manufacturing Item",
-  "cmd.cam_export": "Export CAM Artifact",
-  "cmd.cam_export_result": "Collect CAM Export",
-  "cmd.cam_generate": "Generate Toolpaths",
-  "cmd.cam_holes_from_selection": "Use Selected Holes",
-  "cmd.cam_inspect": "Inspect Manufacturing",
-  "cmd.cam_job_cancel": "Cancel CAM Job",
-  "cmd.cam_job_status": "CAM Job Status",
-  "cmd.cam_operation_order": "Reorder Operations",
-  "cmd.cam_operation_put": "Milling Operation",
-  "cmd.cam_post": "Post Reference G-code",
-  "cmd.cam_program_put": "NC Program",
-  "cmd.cam_setup_put": "Milling Setup",
-  "cmd.cam_simulate": "Simulate Toolpaths",
-  "cmd.cam_tool_put": "Tool Library",
   "cmd.canvas_calibrate": "Calibrate Canvas",
   "cmd.canvas_decal": "Decal",
   "cmd.canvas_delete": "Delete Canvas",
@@ -1129,7 +1113,6 @@
   "ui.heading_design": "DESIGN",
   "ui.heading_draft": "DRAFT",
   "ui.heading_edit": "EDIT",
-  "ui.heading_export": "EXPORT",
   "ui.heading_extrude": "EXTRUDE",
   "ui.heading_fillet": "FILLET",
   "ui.heading_finish_sketch": "FINISH SKETCH",
@@ -1142,7 +1125,6 @@
   "ui.heading_make": "MAKE",
   "ui.heading_measure": "MEASURE",
   "ui.heading_mesh": "MESH",
-  "ui.heading_milling": "MILLING",
   "ui.heading_mirror": "MIRROR",
   "ui.heading_modify": "MODIFY",
   "ui.heading_move": "MOVE",
@@ -1177,12 +1159,10 @@
   "ui.heading_surface": "SURFACE",
   "ui.heading_sweep": "SWEEP",
   "ui.heading_thread": "THREAD",
-  "ui.heading_toolpaths": "TOOLPATHS",
   "ui.heading_top": "TOP",
   "ui.heading_torus": "TORUS",
   "ui.heading_utilities": "UTILITIES",
   "ui.heading_utility": "UTILITY",
-  "ui.heading_verify": "VERIFY",
   "ui.help": "Help",
   "ui.hide": "Hide",
   "ui.hideAxes": "Hide Axes",