[FancyZones] Rework grid editor (#10116)

* Started rewriting

* Making progress

* Fix resizers not moving around

* Implemented splitting, fixed some bugs

* Removed more code, renamed methods

* Merging zones works

* Fix Shift key behavior

* Added spacing (has bugs)

* Implement minimum size restriction

* Match preview and editor visuals

* Snapping works

* Show when splitting is not possible

* Fix spell checker complaining

* Tweak FZ Lib function computing grid zones

* Fix potential crash when loading old zone layouts

* Fix dead objects talking

* Fix splitters being shown when they shouldn't be

* Fix index numbering

* Fix small glitch with the shift key

* Do not snap to borders outside the zone

src/modules/fancyzones/editor/FancyZonesEditor/Overlay.cs

@@ -363,46 +363,5 @@ namespace FancyZonesEditor
                 Monitors.Add(monitor);
             }
         }
-
-        public Int32Rect[] GetZoneRects()
-        {
-            if (_editor != null)
-            {
-                if (_editor is GridEditor gridEditor)
-                {
-                    return ZoneRectsFromPanel(gridEditor.PreviewPanel);
-                }
-                else
-                {
-                    // CanvasEditor
-                    return ZoneRectsFromPanel(((CanvasEditor)_editor).Preview);
-                }
-            }
-            else
-            {
-                // One of the predefined zones (neither grid or canvas editor used).
-                return _layoutPreview.GetZoneRects();
-            }
-        }
-
-        private Int32Rect[] ZoneRectsFromPanel(Panel previewPanel)
-        {
-            // TODO: the ideal here is that the ArrangeRects logic is entirely inside the model, so we don't have to walk the UIElement children to get the rect info
-            int count = previewPanel.Children.Count;
-            Int32Rect[] zones = new Int32Rect[count];
-
-            for (int i = 0; i < count; i++)
-            {
-                FrameworkElement child = (FrameworkElement)previewPanel.Children[i];
-                Point topLeft = child.TransformToAncestor(previewPanel).Transform(default);
-
-                zones[i].X = (int)topLeft.X;
-                zones[i].Y = (int)topLeft.Y;
-                zones[i].Width = (int)child.ActualWidth;
-                zones[i].Height = (int)child.ActualHeight;
-            }
-
-            return zones;
-        }
     }
 }