[add_tlc] send a lot of random hashes for add_tlc

[gpBlockchain]

1. open_channel(max_tlc_number_in_flight: 10000000)
2. send a lot of random hashes for add_tlc

   curl --location 'http://127.0.0.1:8228' --header 'Content-Type: application/json' --data '{
   "id": 42,
   "jsonrpc": "2.0",
   "method": "add_tlc",
   "params": [
       {
           "channel_id": "0xe0692e1fd9ccba27f30a23fd3c70da2df1a7ecce29b78839382c08b1750b3df8",
           "amount": "0x64",
           "payment_hash": "0x52226b2d260888c7b31b15b2a984084e82af6d5ead6b28a786c863bae233032f",
           "expiry": 400,
           "hash_algorithm": "sha256"
       }
   ]
   }'
   {"jsonrpc":"2.0","result":{"tlc_id":"0x15c"},"id":42}

Node1 and Node2 logged a lot of messages, If we establish a connection with the boot_node and then stress test add_tlc, I wonder if it could cause a DDoS attack.

node1 log: node1.add_tlc.log node2 log: node2.add_tlc.log