Import translations from Endless

Much of this code previously lived in Endless's fork of
gnome-control-center, and so many strings had previously been translated
there. I imported a bunch of them from
https://github.com/endlessm/gnome-control-center/tree/eos3.7 as follows:

    cp ~/src/endlessm/gnome-control-center/po/LINGUAS po
    ninja -C _build/ meson-malcontent-update-po
    for x in po/*.po; do
        t3k copy ~/src/endlessm/gnome-control-center/$x $x
    done
    ninja -C _build/ meson-malcontent-update-po

Then manually reviewed the output from t3k to exclude languages where
only trivial translations such as "Help" were copied.

Many of these translations are for OARS rating descriptions, which are
actually originally from gnome-software, and were imported into our
gnome-control-center in a similar way. I have long been sad that these
strings were not present in some common shared library; hooray! now they
are.

[t3k]: https://gitlab.gnome.org/wjt/translate-o-tron-3000/

po/LINGUAS

@@ -1,4 +1,49 @@
+af
+ar
+bg
+bn
+ca
+ca@valencia
+cs
+da
+de
+el
+eo
+es
+eu
+fa
+fi
+fr
+fur
+gd
+gl
+he
+hi
+hr
+hu
 id
+it
+kk
+ko
+lt
+lv
+ml
+ms
+nb
+nl
+oc
+pa
 pl
+pt
 pt_BR
+ro
+ru
+sk
+sl
+sr
+sr@latin
+sv
+th
+tr
 uk
+vi