Implemented proper map popup with navigation

lib/widgets/map_popup.dart

@@ -0,0 +1,60 @@
+import 'package:flutter/material.dart';
+import 'package:intl/intl.dart' as intl;
+
+import '../model/flood_station.dart';
+
+class MapPopup extends StatelessWidget {
+  const MapPopup(
+      {super.key, required this.station, required this.onShowTapped});
+  final FloodStation station;
+  final Function() onShowTapped;
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      title: Text(station.label),
+      content: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Row(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Icon(Icons.home_outlined),
+              Padding(padding: EdgeInsets.only(left: 8)),
+              Text(station.town.isEmpty ? '-' : station.town),
+            ],
+          ),
+          Row(
+            children: [
+              Icon(Icons.water),
+              Padding(padding: EdgeInsets.only(left: 8)),
+              Text(station.riverName.isEmpty ? '-' : station.riverName),
+            ],
+          ),
+          Row(
+            children: [
+              Icon(Icons.calendar_month_outlined),
+              Padding(padding: EdgeInsets.only(left: 8)),
+              Text(
+                station.dateOpened != null
+                    ? intl.DateFormat.yMd().format(station.dateOpened!)
+                    : '-',
+              ),
+            ],
+          )
+        ],
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.of(context).pop(),
+          child: Text('dismiss'),
+        ),
+        TextButton(
+          onPressed: onShowTapped,
+          child: Text('show'),
+        ),
+      ],
+    );
+  }
+}