refactor: conditionally render the create order button based on filtered orders state

apps/mobile/packages/features/client/view_orders/lib/src/presentation/pages/view_orders_page.dart

@@ -222,6 +222,7 @@ class _ViewOrdersViewState extends State<ViewOrdersView> {
                         fontWeight: FontWeight.bold,
                       ),
                     ),
+                    if (state.filteredOrders.isNotEmpty)
                       UiButton.primary(
                         text: t.client_view_orders.post_button,
                         leadingIcon: UiIcons.add,