Steps to reproduce
==================
1. Visit the website and open the event tab.
2. Access an event with the talks and exhibitor sub-menu.
3. Select the talks sub-menu and search for a talk
-> Even if the talk exists, the search count shows zero
-> The same thing happens in the exhibitor sub-menu

Technical
==========
When searching for the talk or the exhibitor we didn't send the search_count due
to this, it is always showing zero.
A variable sponsor is renamed to sorted_sponsors as it was redeclared in the
loop before the return dict.

After this commit
=================
Now the search_count will display the accurate result.

Task-3659940

closes odoo/odoo#147876

Signed-off-by: Warnon Aurélien (awa) <awa@odoo.com>