Add padding to the chat view when shown as the main view
Add padding to the chat view when shown as the main view

The lateral padding is the same used for the chat view when shown in the
sidebar (due to the padding from the tab itself). The same value was
used for the top padding to provide a consistent "frame".

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

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed