QmlDesigner: Fix focus issues in material browser

Fixed focus loss on context menu close.
Fixed an issue with main view also handling cursor and enter keys when
editing material name.
Expanding a section now focuses the expanded section.
Dragging items from content library now focuses correct section.

Fixes: QDS-9215
Change-Id: I2176c7e52d8855c547db426b55ab739ca8f1db06
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

src/plugins/qmldesigner/components/contentlibrary/contentlibraryview.cpp

@@ -323,6 +323,8 @@ ModelNode ContentLibraryView::createMaterial(const NodeMetaInfo &metaInfo)
     VariantProperty objNameProp = newMatNode.variantProperty("objectName");
     objNameProp.setValue(newName);
 
+    emitCustomNotification("focus_material_section", {});
+
     return newMatNode;
 }