Add client config `request_timeout`

[amaury1093]

I saw there's a request_timeout on the server config, that makes sense.

However, I think it can be useful to also set a client config request_timeout. So basically, if the client on is set, then take that as timeout, or else default to the server config's request_timeout.

Does that make sense to add to this lib?

[dizda]

Hey @amaurym,

Yes it does make sense, feel free to send a PR.

[GlenDC]

I'm sending a PR your wait. Defintely something that I would like to have as well.