Feature Request: Support basic authentication when using a proxy

[drazisil-codecov]

Is your feature request related to a problem? Please describe.

According to the documentation, we should use the -U / --upstream args to enable proxy support. However, after trying this and examining the implementation details, it seems that this switch doesn't work for a proxy that requires basic authentication, such as --upstream=http://alice:pass@proxy.com/ .Could you please let me know if I'm mistaken and if there's a way to use codecov_uploader with a proxy that requires authentication?

also, as we see from the code, ProxyAgent from undici is used for the call, and it seems that "auth mode" is not supported for string argument passed by uploader.

This works:
"codecov_uploader -r ${repo} -C ${revision} -u ${server} / -f /coverage.xml -X network -F ${test_name}"

But this doesn't work:
"codecov_uploader --upstream http://user:pass@private_proxy.com/ -r ${repo} -C ${revision} -u ${server} -f coverage.xml -X network -F ${test_name}"

Describe the solution you'd like

A way to pass proxy credential to the uploader

Additional context

Opened on behalf of a customer