BEFORE THIS COMMIT
The option adding an extra register button in top right
(at submenu height) of an event website page was presented as a
checkbox 'Register Button' on event form and 'Add Register Button'
on event type form.This was easily mistaken as the option of
allowing / preventing user registrations, which is not the case at all.
AFTER THIS COMMIT
In both event.event and event.type, this option is renamed
'Extra Register Button' to clarify its purpose and prevent such
a confusion.
--- Links ---
Task Id - 2578891
COM PR - odoo/odoo#72686
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>