Fix Windows compatibility for v5

[programmer04]

Currently, version v5 of the library cannot be used on Windows, let's try

go test ./statsd

ends

# github.com/DataDog/datadog-go/v5/statsd [github.com/DataDog/datadog-go/v5/statsd.test]
statsd\statsd.go:264:25: too many arguments in call to newUDSWriter
        have (string, time.Duration)
        want (string)
statsd\uds_windows.go:8:33: undefined: io
FAIL    github.com/DataDog/datadog-go/v5/statsd [build failed]
FAIL

This PR fixes it, by

• adding missing import io (change has been already proposed by Fix missing import #241, thanks @evanj)
• updating arguments expected by newUDSWriter for Windows
• increasing timeouts (I run it on flaky Windows VM with limited resources and original timeouts weren't sufficient, I've seen similar fix Fix flaky test on slow runner #239)

In the future could you add CI testing on Windows too? It'll allow catching quickly such things before releases and save your time. Moreover, I recommend including macOS too, even if the library hasn't had this problem. I know that both systems are mostly Unix like and should be compatible, but some differences may exist (e.g. I stumbled in my project on the fact that Linux has syscall gettid and macOS doesn't). Errors may appear in the future so it's better to be extra cautious.

[hush-hush]

Thanks for the PR !