Missing FQDN/hostname option for windows

[patryk4815]

Missing FQDN option for windows:

Example implementation:
https://github.com/elastic/go-sysinfo/blob/main/providers/windows/host_windows.go#L88C44-L88C81

os.Hostname() don't return full hostname on windows

[shirou]

Indeed, this might be a good feature to have. And it looks like it could be implemented on all platforms. Thanks for the suggestion.

[john-behm-bertelsmann]

might make sense to introduce a FQDN() function instead of changing the Hostname()