Fix #14259 #15621 (#16322) [backport:1.4]
Fix #14259 #15621 (#16322) [backport:1.4]

* IPv6 text representation according to RFC 5952

* Revert IPv6 text representation according to RFC 5952

* fix #14259 #15621

fix #14259 #15621

* Update lib/system/io.nim

* reverted IoHandle removal

* adaptation of types for WinAPI

Co-authored-by: Andreas Rumpf <135dcb83a9ab360d374a6872197bb8d57db605a4@web.de>
dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim