Typescript for is_canceled and is_encrypting_routes

[alexbosworth]

Version 10.19.0 introduced some changes for the upcoming LND 0.18.3 release:

• createInvoice: add is_encrypting_routes as boolean argument to enable route blinding

• pay, subscribeToPastPayment, subscribeToPayViaDetails, subscribeToPayViaRequest, subscribeToPayments: Add is_canceled as failure returned status to indicate payment loop was terminated

Need typescript modifications

ping @bkiac

[bkiac]

seems like is_canceled is not used in https://github.com/alexbosworth/lightning/blob/master/lnd_methods/offchain/pay.js yet