Add delay and spinner for station map, common const and component for delay

web/src/components/LoadingSpinner.tsx

@@ -0,0 +1,10 @@
+import { Component } from "solid-js";
+
+export const LoadingSpinner: Component<{ text: string; }> = ({ text }) => {
+    return (
+        <div>
+            <span class="spinner"></span>
+            <span style={{ "padding-left": "16px" }}>{ text }</span>
+        </div>
+    );
+}

web/src/components/chart/CityChart.tsx

@@ -13,6 +13,8 @@ export const CityChart: Component<{
     const [getCanvas, setCanvas] = createSignal<HTMLCanvasElement>();
     const [getIsLarge, setIsLarge] = createSignal(false);
 
+    console.log("props.data()", props.data());
+
     let chart: Chart | undefined;
     const data: [string, number | null][] = props.data().map(([dateStr, value]) => [
         formatDateString(dateStr),