Render quotes in comments

[mal-tee]

E.g. in https://data-editor.datenanfragen.de/#/review/3016 it looks like Benni just said the same thing as I did, but it was

quoted.

[baltpeter]

This is actually just a CSS issue. The markup is correct, but we have no styles for blockquote.

I know that some Bootstrap themes add a .markdown class for this purpose (e.g. https://docs.tabler.io/ui/base/typography#markdown-elements). We might want to use that as a reference and fix this for more than just blockquote, while we're at it: https://github.com/tabler/tabler/blob/e4e1ff40c197f46056e8b3dd69c523b68afae33c/core/scss/ui/_markdown.scss#L4