CodeResponse i18n.

Ticket: [BLD-722](https://edx-wiki.atlassian.net/browse/BLD-722) .

Result for CodeResponse:
```
#: common/lib/capa/capa/responsetypes.py:1868
msgid "No answer provided."
msgstr ""

#: common/lib/capa/capa/responsetypes.py:1887
msgid "Error checking problem: no external queueing server is configured."
msgstr ""
```
@olmar please review.