UI/UX: Add newlines to code blocks

[Mochitto]

As of now, code blocks use display: block on the spans that represent a line.
This means that when you are copying from the code-block, the text will not have newlines, returning the code as a single line.

Possible solutions:

1. Using a block element instead of spans. This could be recognized as a block that has a newline after it when copying.
2. Adding invisible <br>. Those should be recognized as newlines when copying.

[t1enneRT]

Suggestion. Using white-space: pre-wrap; on the code-block should solve this!