Bug 20330: Allow translating more of quote upload

Bug 20330: Allow translating more of quote upload

Translate the error messages, and the table headers.

Test plan:

1) Go to Home -> Tools -> Quote editor -> Import quotes
2) Upload quotes from a file. Try to trigger the error messages
3) On successful import, check the table header texts
4) Apply patch, update & install a language
5) The error messages and the table header texts should
   show up in the xx-YY-staff-prog.po
6) Repeat 1,2,3

Signed-off-by: Pasi Kallinen <pasi.kallinen@joensuu.fi>
Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>