Add support for DLC management

[Mixaill]

At the moment there is no possibility to manage the DLC in the integrations.

From the integration side, it seems, it is necessary to add an additional handler to handle the modified game settings.

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Proposed API changes:

• LocalGame
  • add field dlcs: Optional[List[Dlc]]
• Plugin
  • add handler update_game_configuration(game : LocalGame) -> bool

[apawlowskij]

DLC is big and complex topic which needs to be addressed not only in plugins. It's in our backlog, but no real ETA

[Domino5555]

What about DLC for PlayStation 3 games?