Avoid unmapped layers

ViewGetLayers returns the item layer even if it is invalid.  We filter
this out at the base and skip items that cannot be displayed in the
view.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/21368

common/view/view.cpp

@@ -312,6 +312,15 @@ void VIEW::Add( VIEW_ITEM* aItem, int aDrawPriority )
     aItem->m_viewPrivData->m_cachedIndex = m_allItems->size();
 
     std::vector<int> layers = aItem->ViewGetLayers();
+
+    std::erase_if( layers, []( int layer )
+    {
+        return layer < 0 || layer >= VIEW_MAX_LAYERS;
+    } );
+
+    if( layers.empty() )
+        return;
+
     aItem->viewPrivData()->saveLayers( layers );
 
     m_allItems->push_back( aItem );