added sent and id column again for add_cam_main

id checks if entry already exists. sent says if the entry is already
sent to the db

lib/methods/place_db_helper.dart

@@ -64,10 +64,10 @@ class PlaceDBHelper implements IDb{
   }
 
   @override
-  Future<void> updateMainEntry(Map<String, String> place) async {
+  Future<int> updateMainEntry(Map<String, String> place) async {
     var placeDBClient = await dB;
 
-    await placeDBClient
+    return await placeDBClient
         .update('place', place, where: "ID = ?", whereArgs: [place['ID']]);
   }