Make AppodealAdType enum

[JSBmanD]

As dart supports complex enums, it will be great to make AppodealAdType as enum with fields.

Example:

enum AppodealAdType {
  interstitial(android: 0, ios: 1, sios: 3),
  rewardedVideo(android: 0, ios: 1, sios: 3),
  banner(android: 0, ios: 1, sios: 3);

  const AppodealAdType({
    required this.android,
    required this.ios,
    required this.sios,
  });

  final int android;
  final int ios;
  final int sios;
}