Fixes (#435)

* Add flight level field to PIREP field closes #401

* Default value for distance 0 closes #400

* Block airline deletion if assets exist #367

* Formatting

* Move some of the base exception classes

* Fix skin references to use settings table

* Set default for theme name if setting is wrong

app/Exceptions/UserNotAtAirport.php

@@ -5,7 +5,7 @@ namespace App\Exceptions;
 use App\Models\Airport;
 use App\Models\User;
 
-class UserNotAtAirport extends HttpException
+class UserNotAtAirport extends AbstractHttpException
 {
     public const MESSAGE = 'Pilot is not at the departure airport';