Fix untranslatable city/region/country names

This fixes the whole city translation because kstars/geolocation.cpp
relies on the old i18n contexts like "Country name", etc.

The context strings are now again descriptive and also avoid merged
strings that cannot be translated properly.

This commit does not break the string freeze because all
city/region/country names were previously untranslatable.

CCMAIL: kde-i18n-doc@kde.org