i18n: fix spelling of Kyiv

- Add Ukranian translations of zone names. Since I don't write
   Ukranian, add only a translation (er .. in this case, the
   proper original spelling) of Kyiv.
 - Fix spelling in English following UN resolution.
 - Dutch remains unchanged, since as far as I can tell the Dutch
   Government still sticks to the Soviet-era spelling.

FIXES #1298

lang/tz_en.ts

@@ -1285,7 +1285,7 @@
         <location filename="../src/libcalamares/locale/ZoneData_p.cxxtr" line="253"/>
         <source>Kiev</source>
         <comment>tz_names</comment>
-        <translation type="unfinished"></translation>
+        <translation>Kyiv</translation>
     </message>
     <message>
         <location filename="../src/libcalamares/locale/ZoneData_p.cxxtr" line="254"/>