[RPC] WS server never implements ws namespace configurations

[sieniven]

Context

• RPC server when websocket is enabled (ws: true) never implements websocket namespace configurations
• Ws namespace configurations are also not specified on the node's flags
• The API handler of the RPC server will serve on the HTTP endpoint specified with HTTP namespace configs, not on ws namepace configs
• Full context of the issue: https://github.com/okx/xlayer-erigon/compare/dev...okx:xlayer-erigon:niven/fix-ws?expand=1

[mandrigin]

Hey!

thanks!

always happy to get a contribution for that