D23772: Make less use of deprecated enum alias NET::StaysOnTop

[Vlad Zagorodniy]

zzag edited reviewers, added: KWin; removed: Frameworks.

REPOSITORY
  R278 KWindowSystem

REVISION DETAIL
  https://phabricator.kde.org/D23772

To: kossebau, #kwin, #frameworks
Cc: kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns