Add User Settings Entity

Id
NewsletterSubscription => Enum => Nothing, All, UserUpdates, SiteUpdates
UserLevel => Enum => Free, Premium, Super
DefaultLanguage => string => Default Value: en-US
DefaultDirection => Enum => ltr, rtl => Default Value: ltr
UserId => FK => Users

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Create
Update
ChangeUserLevel
Unsubscribe
Subscribe
ChangeLanguage
ChangeDirection