MAPG-111 query map area from DB

modify calculations to be in square km (instead of m)

src/Repository/MapRepository.php

@@ -8,7 +8,7 @@ class MapRepository
     public function getById(int $mapId)
     {
         $select = new Select(\Container::$dbConnection, 'maps');
-        $select->columns(['id', 'name', 'description', 'bound_south_lat', 'bound_west_lng', 'bound_north_lat', 'bound_east_lng']);
+        $select->columns(['id', 'name', 'description', 'bound_south_lat', 'bound_west_lng', 'bound_north_lat', 'bound_east_lng', 'area']);
         $select->whereId($mapId);
 
         return $select->execute()->fetch(IResultSet::FETCH_ASSOC);