Arvin

Adding implementation notes here, I believe we'd be persisting values from the returns of these two functions: - https://github.com/alexbosworth/ln-service#payViaRoutes - https://github.com/alexbosworth/ln-service#payviapaymentdetails

Adding some other things we'd like to persist as well: - Add preimage to `PayInvoiceResult` type and persist in medici (see [comment](https://github.com/GaloyMoney/galoy/pull/598#discussion_r721499238))

Draft of this being built on [`persist-ln-payment-in-medici`](https://github.com/GaloyMoney/galoy/tree/persist-ln-payment-in-medici) branch I'm using our `LnLookupPayment` type to persist data to mongoDB, the new `"payment"` property object in the transactions collection looks like this...

> Hey @vindard I started working on this but am having trouble initiating lnInvoiceCreate to get a paymentRequest to start investigating lnInvoiceFeeProbe > Do I need to be using a...

> Ahh ok that makes sense > Not yet but I would love to join! [Can join here](https://join.slack.com/t/galoymoney-workspace/shared_invite/zt-rvnhsdb5-72AZCD_jzw6_Q05aCs0SgA)

Related to #1203

Possible fixed by #1301

> could you clarify the use case for having the balance of unconfirmed transaction? From one of the ATM folks integrating our API: > ".. it's literally just displayed for...

I was looking into a related issue with this. If we decide to go ahead, we'd need to expand the graphql `Transaction` type to include context about which wallet it's...

Some notes @dolcalmi and I took from a call today thinking through some of this. **For `payment` & `fee_reimbursement` transaction types:** ``` { feeUsd (prod) displayCurrencyFee (in dollars) feeUsd (dev)...