document portal: Move locking explicitly into portal handlers
document portal: Move locking explicitly into portal handlers

This is requires because do i/o on the passed in fd in add() and
if you pass in a fd on the fuse mount itself we deadlock.

thiblahute/xdg-app,thiblahute/xdg-app,matthiasclasen/flatpak,GeorgesStavracas/flatpak,GeorgesStavracas/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,chergert/xdg-app,thiblahute/xdg-app,handsome-feng/flatpak,flatpak/flatpak,alexlarsson/xdg-app,chergert/xdg-app,matthiasclasen/flatpak,amigadave/flatpak,alexlarsson/xdg-app,GeorgesStavracas/flatpak,amigadave/flatpak,handsome-feng/flatpak,handsome-feng/flatpak,GeorgesStavracas/flatpak,matthiasclasen/xdg-app,handsome-feng/flatpak,amigadave/flatpak,GeorgesStavracas/flatpak,matthiasclasen/xdg-app,flatpak/flatpak,alexlarsson/xdg-app,thiblahute/xdg-app,flatpak/flatpak,chergert/xdg-app,flatpak/flatpak,flatpak/flatpak,matthiasclasen/xdg-app,amigadave/flatpak,handsome-feng/flatpak,chergert/xdg-app,alexlarsson/xdg-app,matthiasclasen/flatpak,matthiasclasen/xdg-app