filechooser: Make filtering work again

One too many lines were dropped when this filter combo
was converted to a dropdown. Bring it back, to make
filtering work again.
10 jobs for matthiasc/for-master in 46 minutes and 29 seconds
Status Job ID Name Coverage
  .Pre
passed #795039
style-check-diff

00:00:48

 
  Build
passed #795040
fedora-x86_64

00:10:55

passed #795042
win32-ps
msys2-mingw64

00:03:31

passed #795076
release-build

00:06:20

failed #795041
release-build

00:13:36

 
  Analysis
passed #795043
static-scan

00:16:24

 
  Docs
passed #795044
reference

00:12:00

 
  Flatpak
manual #795045
flatpak allowed to fail manual
flatpak-manual:demo
manual #795047
flatpak allowed to fail manual
flatpak-manual:icon-browser
manual #795046
flatpak allowed to fail manual
flatpak-manual:widget-factory