Add config option for number of events queried at once when clearing pending packets

[romac]

Summary

Add a config option for the number of events queried at once when clearing pending packets.

Problem Definition

Right now, this value is hardcoded at 50:

hermes/crates/relayer/src/link/packet_events.rs

Line 18 in b98ca86

pub const CHUNK_LENGTH: usize = 50;

This is sometimes too high, eg. when some packets are huge, as experienced by the Informal Staking team where the node would error out with a 400 Bad Request when pulling the packet data during a packet clearing:

{
  "timestamp": "2023-12-29T13:39:06.465721Z",
  "level": "ERROR",
  "fields": {
    "message": "gas estimation failed or encountered another unrecoverable error",
    "error": "RPC error to endpoint http://10.10.11.102:26740/: HTTP request failed with non-200 status code: 400 Bad Request"
  },
  "span": {
    "account.sequence": "273283",
    "chain": "osmosis-1",
    "name": "send_tx_with_account_sequence_retry"
  },
  "spans": [
    {
      "name": "spawn"
    },
    {
      "chain": "sifchain-1",
      "name": "chain"
    },
    {
      "client": "07-tendermint-41",
      "name": "client"
    },
    {
      "connection": "connection-20",
      "name": "connection"
    },
    {
      "channel": "channel-17",
      "name": "channel"
    },
    {
      "dst_chain": "osmosis-1",
      "src_chain": "sifchain-1",
      "src_channel": "channel-17",
      "src_port": "transfer",
      "name": "worker.packet"
    },
    {
      "odata": "cleared/1d1b81d2 ->Destination @1-15371999; len=50",
      "name": "relay"
    },
    {
      "chain": "osmosis-1",
      "tracking_id": "cleared/1d1b81d2",
      "name": "send_messages_and_wait_check_tx"
    },
    {
      "account.sequence": "273283",
      "chain": "osmosis-1",
      "name": "send_tx_with_account_sequence_retry"
    }
  ],
  "threadId": "ThreadId(134)"
}

Proposal

• Add a per-chain query_packets_chunk_size setting to config.toml with a default value of 50 and use that instead of CHUNK_LENGTH.
• Add a --query-packets-chunk-size=N CLI flag to clear packets which overrides the query_packets_chunk_size if present.

Acceptance Criteria

As per above.

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