I love the idea of this pull request, but `WINEHIDEWAIT` seems meh.
https://www.winehq.org/docs/wine <- There is doc with all other env variables.
`WINEBOOT_HIDE_DIALOG` seems more something I'll prefer, I'll share this MR with wine-tkg community to see which names they prefer.
Since how the variable name is entirely cosmetic, there is no right or wrong answer as long as it match the spirit of other env variables.