Increase gap limit about sparrow

[craigraw]

This would be a code change right now, albeit a simple one. I will add support for it as a configuration setting.

[craigraw]

Wallet configurable gap limit added in 38b27bb through an 'Advanced' dialog on the Settings panel.

[craigraw]

It's unclear why the m/44'/0'/0'/0/18 derivation is not pulling in earlier transactions though. It does not matter that there is no UTXO for this script hash. Assuming Electrum and Sparrow are talking to the same Electrum server instance, the RPC call is the same. Assuming the wallet is setup correctly and the addresses it is generating are correct, this call should return the same result.

Also, it looks like there are many addresses in this wallet that have had previous transactions with spent outputs - like most wallets Sparrow will keep incrementing the derivation path if it finds there are previous transactions until the gap limit is reached, regardless of whether those transaction outputs are spent or not. Is this behaviour consistent with what you're seeing?