Improve ASB to Electrum query method

[darkness-su]

From Electrum server logs:
mainnet_electrs | [2024-11-10T23:18:57.113Z INFO electrs::electrum] your wallet uses less efficient method of querying electrs, consider contacting the developer of your wallet. Reason: blockchain.scripthash.get_history called for unsubscribed scripthash

[Einliterflasche]

This will be addressed as part of our bdk upgrade (#98).

[binarybaron]

This will be addressed as part of our bdk upgrade (#98).

I do not think we should switch to using stateful electrum apis. We haven't had an issue where we were "banned", and the point of electrum is to allow stateless querying of the blockchain.