Add extra node timeout setting & json-rpc client connection setting

[0Tech]

The subject of the triage:

• chore: connection pool and read timeout ostracon#131

[tkxkd0159]

Ref.

1. https://github.com/cometbft/cometbft/blob/main/node/node.go#L721-L729
2. https://github.com/Finschia/ostracon/blob/v1.1.2/node/node.go#L1153-L1166

This issue contains two issues

1. [json-rpc server] cometbft still set ReadTimeout, WriteTimeout, IdleTimeout with default value [10, 10, 10] and don't support to change this value in config.toml. WriteTimeout changes only depending on TimeoutBroadcastTxCommit in config.toml. It's worth suggesting a change to the upstream, but it's also possible that they don't want it.
2. [json-rpc client] Ostracon sets MaxIdleConns, MaxIdleConnsPerHost, IdleConnTimeout, ExpectContinueTimeout for json-rpc client [10000, 10000, 60sec, 1sec] whereas cometbft didn't and use default value [no limit, 2, no limit, no limit]
   I don't think it's a necessary change. So if we want to apply this change to upstream, we need to show benchmark test to prove performance improvement.