Request timeout configuration

[crepererum]

Currently the jsonrpsee client is constructed using the default configuration here:

lsp-client/src/lib.rs

Line 48 in ecbd7fc

let client = ClientBuilder::default().build_with_tokio(sender, receiver);

According to the upstream docs the default request timeout is 60s. For some settings it might be desirable to change this, either via another parameter or via a builder of the LspClient.