LN Cash Out Fee Estimation Display

[swedishfrenchpress]

Per twitter user @tomtomatoh "In this part of the UI would it make sense to cache the fee estimation so that user’s need only input the number of sats to cash out?...I can look into it if it ends up in a ticket. Might make sense to use something like swr, to display a value on subsequent redeems within the same session. That’s something I use on web, not sure if swr would be the appropriate package for mobile

Per @callebtc "in that case, most lightning wallets don't show you the fee at all. They let the user enter the amount and if the fee is in a range that the wallet accepts, such as "not more than 10 sats or 2% of the amount" then the payment is initiated. so it will either let the user specify the max fee percentage or max fee in satoshi, or have those limits hard coded and just accept anything below that. that way you have to think about fees only once when changing the settings, the rest is always ok"

Based on the feedback from calle and how most wallets don't show a fee estimate, I'm not really sure if we need to change anything here. I'm thinking we should just keep it as it is. What the users feedback mainly was, as far as I get it, is to enter in the exact amount of sats they want to send with Lightning and need to calculate the fee into their total. If I've got it right about how eNuts works, the number you enter is exactly what the receiver gets. The fee gets added onto the total payment, and is taken out of your balance. Is this how it works @KKA11010