Merge upstream, including cached config lookups in G-code export

Three commits: G-code export caches its filament config slot and repeated
option lookups, per-plate bed type overrides follow the printer's multi-bed
support, and the gizmo checkboxes and texture displacement panel get styling
and refresh fixes. No conflicts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/slic3r/GUI/MainFrame.cpp

@@ -3894,6 +3894,8 @@ bool MainFrame::load_config_file(const std::string &path)
         return false;
     }
     wxGetApp().load_current_presets();
+    if (Plater *plater = wxGetApp().plater())
+        plater->normalize_bed_types(false);
     return true;
 }