Reference Diff:
https://github.com/Joystream/orion/pull/201/files#diff-b30b20a376a80a6ef07f60df529cfb991a5aa361fb99f5f1a1d701c893bc243d

Next Entity Id counter migrations:

• correctly set NextEntityId for entityName = Account

Properties being added to the Account Entity

• referrerChannelId: String, default value null
• notificationPreferences: NotificationPreferences default value: all notifications (email and inApp are enabled)
• notifications, default value []

Properties being added to the Channel entity

• yppStatus: YppStatus default value YppStatusUnverified: This means that if we want orion to store information that channels are verified in the ypp sense then we should migrate them manually in some way @dmtrjsg

Bug

There's an issue concerning the overlay, that is able to overwrite NextEntityId with outdated pre-migration values.