Add SyncOptions as the second argument to Wallet::sync

The current options are awkward and it would be good if we could
introduce more in the future without breaking changes.

src/blockchain/esplora/ureq.rs

@@ -109,10 +109,10 @@ impl GetHeight for EsploraBlockchain {
 }
 
 impl WalletSync for EsploraBlockchain {
-    fn wallet_setup<D: BatchDatabase, P: Progress>(
+    fn wallet_setup<D: BatchDatabase>(
         &self,
         database: &mut D,
-        _progress_update: P,
+        _progress_update: Box<dyn Progress>,
     ) -> Result<(), Error> {
         use crate::blockchain::script_sync::Request;
         let mut request = script_sync::start(database, self.stop_gap)?;