Adds flight,battery models and image file managment

lib/models/flight.dart

@@ -0,0 +1,51 @@
+class Flight {
+  int? id;
+  String name;
+
+  // Timestamp in seconds since epoch
+  int startTimestamp;
+  int endTimestamp;
+
+  // Foreign keys
+  int droneId;
+  int batteryId;
+
+  // Location
+  double? locationLat;
+  double? locationLong;
+
+  Flight({
+    this.id,
+    required this.name,
+    required this.startTimestamp,
+    required this.endTimestamp,
+    required this.droneId,
+    required this.batteryId,
+    this.locationLat,
+    this.locationLong,
+  });
+
+  factory Flight.fromMap(Map<String, dynamic> map) => Flight(
+    id: map["id"],
+    name: map["name"],
+    startTimestamp: map["start_timestamp"],
+    endTimestamp: map["end_timestamp"],
+    droneId: map["drone_id"],
+    batteryId: map["batteryId"],
+    locationLat: map["location_lat"],
+    locationLong: map["location_long"],
+  );
+
+  Map<String, dynamic> toMap() {
+    return {
+      "id": id,
+      "name": name,
+      "start_timestamp": startTimestamp,
+      "end_timestamp": endTimestamp,
+      "drone_id": droneId,
+      "battery_id": batteryId,
+      "location_lat": locationLat,
+      "location_long": locationLong,
+    };
+  }
+}