Use popover as context menu

Fixes Librem5/debs/webkit#14
5 jobs for menu in 99 minutes and 40 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Package
passed #357726
librem5
package-pureos-byzantium

01:19:12

passed #357727
librem5:arm64
package-pureos-byzantium:arm64

01:39:39

 
  Test Package
passed #357729
librem5
autopkgtest-pureos-byzantium-package

00:01:07

passed #357728
librem5
check-tarball

00:02:50

passed #357730
librem5
lintian-pureos-byzantium-package

00:01:25