column: Add the .narrow, .medium and .wide style classes

These classes are added automatically depending on the reached
threshold: .narrow when the column is so narrow it allocates all its
size to its child, .wide when the child won't be allocated more space as
the column grows, .medium in between, and none of these when there is no
child or it isn't visible.
12 jobs for column-style-classes in 29 minutes and 29 seconds (queued for 28 minutes and 39 seconds)
Status Name Job ID Coverage
  Build
passed api-visibility #239893
librem5

00:03:02

passed build-debian-clang #239896
librem5

00:05:41

passed build-debian-gcc #239894
librem5

00:04:01

passed build-debian-gcc-static #239895
librem5

00:03:53

passed build-fedora-gcc #239897
librem5

00:04:16

 
  Test+Docs
passed build-gtkdoc #239898
librem5

00:03:16

passed unit-test #239899
librem5

00:03:12

44.4%
 
  Package
passed package-debian-buster #239900
librem5

00:04:16

passed package-debian-buster:arm64 #239901
librem5:arm64

00:06:38

passed package-flatpak #239902
flatpak

00:02:04

 
  Test Package
passed autopkgtest-debian-buster-package #239903
librem5

00:02:36

passed lintian-debian-buster-package #239904
librem5

00:01:06