feat: Add timeout to BoxNetworkClient

[szynaka]

Occasionally I have seen network requests fail to return and hang a program.

PR #479 adds an optional timeout to be used by the requests library as recommended by their documentation (https://docs.python-requests.org/en/latest/user/quickstart/#timeouts)

It would probably be better to include a default timeout of a few minutes, but that could introduce additional errors to handle. So, instead this change maintains the existing behavior if a timeout is not provided.

This issue was requested because the code in the PR is auto-generated and would need to be integrated into the code-gen engine.