This commit hides "other" tracks/rooms and exhibitor sections if there is only a single record for these. Purpose is: Allow users to handle events that do not have a ton of things happening at the same time without showing empty sections. Example: I use Odoo events to broadcast my concert/zoom conference/... online and want my website to look neat. Task-2531084 closes odoo/odoo#71600 Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>