Added schema for Item management

[Bakk-f4]

let me know what you think about this schema

[itzandroidtab]

Looks pretty good. Some remarks, I dont think we need both the userId and characterId. The inventory is part of the character.

Another thing but that is just my preference. I would shorten the "item_perk_one, item_perk_two, etc" to "perk0, perk1, perk2, etc"

[felipefcunica]

It is probably necessary due to the possibility of having multiple characters associated with the same userID. But if the character ID is a primary key independent of the userID association, we can remove the need to validate the userID.

[FilippoLeone]

@Bakk-f4 could you wait for the alembic merge and generate the revision file ?

Example: alembic revision --autogenerate -m "Added items table"