In 53b3d2f0dc we introduced a stricter BBCode Tag parser. It prevents having "values" with spaces when they're not surrounded by a valid pair of quotes.
The `[details=` BBCode Tag is popular enough that it's worth adding a special case for it (especially since it doesn't support other parameters).
This also adds the Finnish pair of quotes.
Context - https://meta.discourse.org/t/details-accepts-only-one-word-as-summary/313019