refactor: [qt] Use SpanReader to avoid two vector copies

src/qt/recentrequeststablemodel.cpp

@@ -189,8 +189,7 @@ void RecentRequestsTableModel::addNewRequest(const SendCoinsRecipient &recipient
 // called from ctor when loading from wallet
 void RecentRequestsTableModel::addNewRequest(const std::string &recipient)
 {
-    std::vector<uint8_t> data(recipient.begin(), recipient.end());
-    DataStream ss{data};
+    SpanReader ss{MakeByteSpan(recipient)};
 
     RecentRequestEntry entry;
     ss >> entry;