tx_pool: revert #4592 and move bin2hex conversion to on_get_transaction_pool

src/cryptonote_core/tx_pool.cpp

@@ -766,7 +766,7 @@ namespace cryptonote
     m_blockchain.for_all_txpool_txes([&tx_infos, key_image_infos, include_sensitive_data](const crypto::hash &txid, const txpool_tx_meta_t &meta, const cryptonote::blobdata *bd){
       tx_info txi;
       txi.id_hash = epee::string_tools::pod_to_hex(txid);
-      txi.tx_blob = epee::string_tools::buff_to_hex_nodelimer(*bd);
+      txi.tx_blob = *bd;
       transaction tx;
       if (!parse_and_validate_tx_from_blob(*bd, tx))
       {

src/rpc/core_rpc_server.cpp

@@ -924,6 +924,8 @@ namespace cryptonote
       return r;
 
     m_core.get_pool_transactions_and_spent_keys_info(res.transactions, res.spent_key_images, !request_has_rpc_origin || !m_restricted);
+    for (tx_info& txi : res.transactions)
+      txi.tx_blob = epee::string_tools::buff_to_hex_nodelimer(txi.tx_blob);
     res.status = CORE_RPC_STATUS_OK;
     return true;
   }