[FIX] survey: display results of survey with no sections
[FIX] survey: display results of survey with no sections

Since commit https://github.com/odoo/odoo/commit/dba478332681dd21a39c4a183c002b1cf6e046d2, a survey can have questions with no section
associated, which means 'page_ids' field will be empty.

This prevents to display the analysis results of a survey, as we are
still expecting a structure page/questions. To solve it, if a question
does not have a section associated, we use an empty page instead.

closes odoo/odoo#39087

X-original-commit: 45c2964c1cfd07cabfa6a1a1b8e796bea4c521d7
Signed-off-by: Alex Tuyls <dc186632db64fd9aa12a72f292039aee430db898@users.noreply.github.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo