Transactionally modify the wallet DB in `replace_queue_entries`

We don't want to delete old scan range queue entries unless we are
guaranteed to write the updated queue entries.

zcash_client_sqlite/src/wallet/scanning.rs

@@ -426,7 +426,7 @@ pub(crate) fn insert_queue_entries<'a>(
 }
 
 pub(crate) fn replace_queue_entries(
-    conn: &rusqlite::Connection,
+    conn: &rusqlite::Transaction<'_>,
     query_range: &Range<BlockHeight>,
     entries: impl Iterator<Item = ScanRange>,
 ) -> Result<(), SqliteClientError> {