Utility method to read timeout parameter from REST requests

[ywangd]

In #107986, we introduced a utility method to read master_timeout from REST requests. We could use a similar utility method for the timeout parameter as well. Different APIs have different ways to decide the default timeout value. For this issue, we can leave them untouched.

[elasticsearchmachine]

Pinging @elastic/es-distributed (Team:Distributed)

[prathm3]

Hi @ywangd , I would like to work on this this task.

[ywangd]

@prathm3 Thanks for your interests in Elasticsearch. Unfortunately this issue is already assigned internally. I encourage you to look for other issues.