Calendar popovers are now easier to read and navigate. If an event contains a lot of information, its popover now grows tall instead of wide. In case of more than a few attendees, the widget shows a summary and allows the user to expand the full list. The displayed total number of attendees is now accurate, without the default field limit. task-2685440 closes odoo/odoo#112114 Signed-off-by: Arnaud Joset <arj@odoo.com>