Use Ctrl + G to toggle the 3D editor grid visibility by default

The 2D editor grid toggle shortcut has been changed to use
`KEY_MASK_CMD` for consistency. This means it will now use Cmd
on macOS instead of Ctrl.

(cherry picked from commit 2cc053c64b2cafa9326044915c089a0fd0265578)

editor/plugins/canvas_item_editor_plugin.cpp

@@ -5844,7 +5844,7 @@ CanvasItemEditor::CanvasItemEditor(EditorNode *p_editor) {
 
 	p = view_menu->get_popup();
 	p->set_hide_on_checkable_item_selection(false);
-	p->add_check_shortcut(ED_SHORTCUT("canvas_item_editor/show_grid", TTR("Always Show Grid"), KEY_MASK_CTRL | KEY_G), SHOW_GRID);
+	p->add_check_shortcut(ED_SHORTCUT("canvas_item_editor/show_grid", TTR("Always Show Grid"), KEY_MASK_CMD | KEY_G), SHOW_GRID);
 	p->add_check_shortcut(ED_SHORTCUT("canvas_item_editor/show_helpers", TTR("Show Helpers"), KEY_H), SHOW_HELPERS);
 	p->add_check_shortcut(ED_SHORTCUT("canvas_item_editor/show_rulers", TTR("Show Rulers")), SHOW_RULERS);
 	p->add_check_shortcut(ED_SHORTCUT("canvas_item_editor/show_guides", TTR("Show Guides"), KEY_Y), SHOW_GUIDES);

editor/plugins/spatial_editor_plugin.cpp

@@ -6345,7 +6345,7 @@ SpatialEditor::SpatialEditor(EditorNode *p_editor) {
 
 	p->add_separator();
 	p->add_check_shortcut(ED_SHORTCUT("spatial_editor/view_origin", TTR("View Origin")), MENU_VIEW_ORIGIN);
-	p->add_check_shortcut(ED_SHORTCUT("spatial_editor/view_grid", TTR("View Grid")), MENU_VIEW_GRID);
+	p->add_check_shortcut(ED_SHORTCUT("spatial_editor/view_grid", TTR("View Grid"), KEY_MASK_CMD + KEY_G), MENU_VIEW_GRID);
 
 	p->add_separator();
 	p->add_shortcut(ED_SHORTCUT("spatial_editor/settings", TTR("Settings...")), MENU_VIEW_CAMERA_SETTINGS);