Fix homepage lists

[sahircansurmeli]

Lists on homepage extend as long as the data that comes from the API, which breaks the design. Lists on the homepage should only display a fixed number of items, which should not extend beyond one line. Check "New questions in courses enrolled" to see the problem.

• [x] Use itemsPerPage in API requests to limit the number of items coming from the API.
• [x] Display only the text of the html of the question. See: https://stackoverflow.com/questions/28899298/extract-the-text-out-of-html-string-using-javascript
• [x] Limit the number of characters so that the long items get truncated to one line (add "..." if truncated)
• [x] fix myCoursesNewQuestion not rendering on first render