Fix tooltips when chat view is shown in the sidebar
Fix tooltips when chat view is shown in the sidebar

The positioning context (the element that an absolute element is
relative to) of the tooltips shown for the date of messages was the
author row, and thus they were visible only were the author row would be
visible. The author row would be clipped outside the list of messages
(due to its "overflow-y" CSS property), so the tooltip shown for the
date of the newest message was clipped at the top of the list of
messages.

Now the tooltips are added to the chat view itself, so "#app-content"
becomes their positioning context and thus are no longer clipped by the
list of messages.

Signed-off-by: Daniel Calviño Sánchez <bd7629e975cc0e00ea7cda4ab6a120f2ee42ac1b@gmail.com>

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed