Handling of cloze-Tasks

Currently there is support for exporting data from special cloze-qestions to json.

While testing on real exam-data the translation somehow did not succeed on non-special cloze-tasks (see attached: base64 error at the end)log.txt

Anyways, it would be great to have support for general cloze-questions.

Use case: I don't have fully-featured grady-import in mind, but a simple means for the teacher to preprocess given answers.

Example-Question: Enter the first three letters of the alphabet into the field.

Example-Answers: ABC, A B C => teacher does some python-tricks to unify answers to fasten the manual grading of answers inside ILIAS.