* Newer CI images (#12188)

* Bump electronbuilds/electron* versions

The linux-appname branch has been gathering dust for awhile.
Some of the versions in `master` are higher, and some of the
versions in `linux-appname` are higher to add libnotify.

This commit takes the higher of the two numbers in each case.

* Add libnotify to the Dockerfiles

* Linux named notifications (#12192)

* Set name & desktop-entry on Linux notifications

* DBusMock now honors verbose mode flag

* Disable DBus Notification tests on ia32

* Fix desktop-id notification edge case (#12216)

* Fix desktop-id notification edge case

* Extract-method platform_util::GetDesktopName()

This removes duplicated code from libnotify_notifications.cc
and atom/common/linux/application_info.cc.

* Check for empty case in GetDesktopName().

* Move GetDesktopName() to brightray::util

* Remove unnecessary changes in platform_util

* Add a brightray::platform_util namespace

* Bump CI