"isUnblocked" property was added in webhook follow event

[YasSawada]

News URL:
In the Messaging API, you can now determine whether a user has added your LINE Official Account as a friend or unblocked by a webhook follow event
https://developers.line.biz/en/news/2024/02/06/add-friends-and-unblock-friends-can-now-be-determined-by-webhook/

• follow event