Room details: room description

[kerryarchibald]

https://www.figma.com/file/rTaQE2nIUSLav4Tg3nozq7/Compound-Web-Components?type=design&node-id=1073-6237&mode=design&t=PifxQQLUULHatXkK-4

https://www.figma.com/file/wqgXVb7RVaIybfRsXdWEiL/Element-Web-Room-Header-%26-Details?node-id=1478%3A102982&mode=dev

https://www.figma.com/file/wqgXVb7RVaIybfRsXdWEiL/Element-Web-Room-Header-%26-Details?node-id=454%3A51346&mode=dev

AC:

• When room has no topic and user has no edit rights, display nothing
• When room has no topic and user has edit rights, display: 'Add topic' cta that opens room settings dialog
• Rich text topics are rendered correctly
• Emoji in topic is rendered correctly
• Topic is truncated to two lines
• Clicking the caret expands to show the full topic
• When the topic is expanded and the user has rights, an edit button is displayed that opens room settings dialog

[dbkr]

I'm guessing we would probably want to add a compound component for this (I don't see one) so maybe a day for this. I'm also not seeing what the edit link does? If that needs an edit view we don't have, then more.