TRANSACTIONS.INITIAL_UPDATE / HISTORICAL_UPDATE / DEFAULT_UPDATE webhook.
@type t() :: %PlaidEx.Webhooks.Schemas.TransactionsEvent{ environment: String.t(), item_id: String.t(), new_transactions: integer(), removed_transactions: [String.t()], webhook_code: String.t(), webhook_type: String.t() }
@spec from_map(map()) :: t()