Server side characters

[Cybermaxke]

Features:

• Proxy side characters can be enabled by plugins by listening to the InitCharacterStorageEvent and providing a CharacterStorage
• Character storages can be shared between servers, or a specific storage can be provided for a specific storage
• If server side character is enabled on the backing server, that storage will be used instead
• If no character storage is provided, client side characters will be used instead
• Packets and inventory operation validations will be handled by the proxy, saving/loading/deciding which storage can be done through plugins, the characters plugin will provide a basic implementation

[Cybermaxke]

Was merged manually.