D29015: Move screencasting to KWin

apol created this revision.
Herald added a project: KWin.
Herald added a subscriber: kwin.
apol requested review of this revision.

REVISION SUMMARY
  3rd part of the change started by D28882 <https://phabricator.kde.org/D28882> and D28884 <https://phabricator.kde.org/D28884>.
  
  Instead of implementing KWayland::Server::RemoteAccess, we implement
  KWayland::Server::Screencasting and deal with it with ScreenCastStream
  that used to be in xdg-desktop-portal.
  
  This allows us to offer video streams directly from kwin rather than
  building them from the outside (be it xdg-desktop-portal or otherwise).

TEST PLAN
  Not much yet

REPOSITORY
  R108 KWin

BRANCH
  screencast

REVISION DETAIL
  https://phabricator.kde.org/D29015

AFFECTED FILES
  CMakeLists.txt
  plugins/platforms/drm/CMakeLists.txt
  plugins/platforms/drm/drm_backend.cpp
  plugins/platforms/drm/egl_gbm_backend.cpp
  plugins/platforms/drm/egl_gbm_backend.h
  plugins/platforms/drm/screencaststream.cpp
  plugins/platforms/drm/screencaststream.h
  scene.cpp
  toplevel.cpp
  wayland_server.cpp
  wayland_server.h

To: apol
Cc: kwin, Orage, cacarry, LeGast00n, The-Feren-OS-Dev, cblack, jraleigh, zachus, fbampaloukas, mkulinski, ragreen, jackyalcine, iodelay, crozbo, bwowk, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, romangg, jensreuterberg, abetts, sebas, apol, ahiemstra, mart