rpc: allow getting pruned blocks from gettransactions

and get them pruned in find_and_save_rings, since it does not need
the pruned data in the first place.

Also set decode_to_json to false where missing, we don't need this
either.

src/rpc/core_rpc_server.cpp

@@ -227,7 +227,6 @@ namespace cryptonote
       MERROR("Failed to parse and validate tx from blob");
       return cryptonote::blobdata();
     }
-
     return get_pruned_tx_blob(tx);
   }
   //------------------------------------------------------------------------------------------------------------------------------

src/wallet/wallet2.cpp

@@ -5595,7 +5595,18 @@ bool wallet2::find_and_save_rings(bool force)
   for (const std::pair<crypto::hash,wallet2::confirmed_transfer_details> &entry: payments)
   {
     const crypto::hash &txid = entry.first;
-    txs_hashes.push_back(txid);
+    req.txs_hashes.push_back(epee::string_tools::pod_to_hex(txid));
+  }
+
+  MDEBUG("Found " << std::to_string(req.txs_hashes.size()) << " transactions");
+
+  // get those transactions from the daemon
+  req.decode_as_json = false;
+  req.prune = true;
+  bool r;
+  {
+    const boost::lock_guard<boost::mutex> lock{m_daemon_rpc_mutex};
+    r = epee::net_utils::invoke_http_json("/gettransactions", req, res, m_http_client, rpc_timeout);
   }
 
   MDEBUG("Found " << std::to_string(txs_hashes.size()) << " transactions");