fix: fixed schema error and only nodes schema

Schema panel broke interface when opening the pop-up. Also it was not possible to display schema's with only nodes. This fixes it.

libs/shared/lib/schema/pills/nodes/entity/SchemaListEntityPill.tsx

@@ -83,7 +83,7 @@ export const SchemaListEntityPill = React.memo(({ id, selected, data }: NodeProp
                       },
                       {} as Record<string, string>,
                     )}
-                    numberOfElements={schemaStats.nodes.stats[data.name].count}
+                    numberOfElements={schemaStats?.nodes?.stats[data.name]?.count}
                   />
                 </VisualizationTooltip>
               </div>