Change search bar suggestion text

changed the strid in all 3 places in ckan templates, as well as in hdx_theme
- msgid "eg. http://example.com/population-jan-2011.json"
- msgid "eg. Population"
- msgid "eg. January 2011 Population"

- regenerated .pot file
- updated .po files
- added on romanian translation the string for population to be able to test it
- recompiled .mo files
- tested
- all looks good

On this issue, every time we need to change the default string (thats in english) we only need to change the corresponding locale .po file and recompile .mo file