Feature request: adjust gap limit in app settings

[ndeet]

I know you can change the gap limit on startup but this is not easy to explain to unexperienced users (merchants). Is there a reason why this settings can't be done in the UI?

E.g if you use BTCPay Server it is very common for merchants needing to increase the gap limit to see all received transactions. BTCPay does create a new address for each invoice and never reuses it atm. Would be great if this could be configured via the settings UI.