header-bar: Respect CSS min-width and min-height

Fixes Librem5/libhandy#194
12 jobs for wip/exalm/css in 14 minutes and 33 seconds (queued for 2 seconds)
latest
Name Stage Failure
failed
package-flatpak Package
rm: cannot remove '_build/meson-logs/coveragereport/builds/exalm/libhandy/glade/glade-hdy-search-bar.c.func.html': Permission denied
rm: cannot remove '_build/meson-logs/coveragereport/builds/exalm/libhandy/glade/glade-hdy-swipe-group.c.gcov.html': Permission denied
Running after_script
Uploading artifacts for failed job
Uploading artifacts...
_build/meson-logs/meson-log.txt: found 1 matching files

WARNING: sm.puri.Handy.Demo-dev.flatpak: no matching files
Uploading artifacts to coordinator... ok
id=267298 responseStatus=201 Created token=uUhYzoFv
ERROR: Job failed: exit code 1
failed
package-flatpak-glade Package
rm: cannot remove '_build/tests/test-window-handle': Permission denied
rm: cannot remove '_build/tests/test-combo-row': Permission denied
rm: cann
Running after_script
Uploading artifacts for failed job
Uploading artifacts...
_build/meson-logs/meson-log.txt: found 1 matching files

WARNING: sm.puri.Handy.Glade-dev.flatpak: no matching files
Uploading artifacts to coordinator... ok
id=267299 responseStatus=201 Created token=mHi7b-XC
ERROR: Job failed: exit code 1