Generic ITEM webhook (PENDING_EXPIRATION, USER_PERMISSION_REVOKED, etc.).
@type t() :: %PlaidEx.Webhooks.Schemas.ItemEvent{ consent_expiration_time: String.t() | nil, environment: String.t(), item_id: String.t(), webhook_code: String.t(), webhook_type: String.t() }
@spec from_map(map()) :: t()