There is not much room in the inspector window; squeezing a
tree and a detailed view in the same page is not great. Instead,
make the details a separate page.
Tools like damn-lies rely on being able to generate .pot files
from pristine checkouts, so everything that goes into the .pot
file has to be in git. This is not ideal, but we already do
the same for other .ui.h files in GTK+.