check_connections: on windows, use gopsutil to get tcp connections

[inqrphl]

the library uses iphlpapi.dll functions GetTcpTable2, GetTcp6Table2, GetExtendedTcpTable. it also has GetExtendedUdpTable , but they are not used.

the library transforms the connection states to english in common.go . the strings are always in english and not localized. this means check_connection can test for english strings in connection.State without worry.

tested on a machine with german locale, it works. should fix #360

the library only imports standard packages and sys/windows , so it should be safe.

[inqrphl]

ci failing due to docker integration tests on linux, unrelated to PR. waiting for upstream fix.

[c-kr]

Isn't that something the already included gopsutil lib can do: https://github.com/shirou/gopsutil/blob/master/net/net_windows.go

Although net_connections is listed as not supported there seems to be a GetExtendedTcpTable in the mentioned code above

win-netstat looks abandoned - last commit was 8 years ago

[inqrphl]

Thanks @c-kr

Seems like you are correct. I had deepseek v4 pro look into sources, it confirms that it is using the same underlying functions for GetExtendedTcpTable and even converts the status to a string using same mappings from MSDN

pushing a commit that changes library to gopsutil, took like 5 lines

[sni]

Great, one less sub process call. Thanks.