Handle newlines in user pills (#11166)
* Handle newlines in user pills
Fixes: vector-im/element-web#10994
* Fix typo in comment
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Refactor link generation for better readability
* Use `<br>` instead of `<br/>`
* Fix copy/paste error
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Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
