[FIX] web: convert python/js bool values in read_progress_bar

Because of an issue with converting bool values, read_progress_bar didn't work
on grouping by bool fields (e.g. Active).

Related tests worked fine because mocked server responses were different from
real server responsed. So, we need to adjust mocked server too.

opw-2870937

closes odoo/odoo#95654

Signed-off-by: Julien Mougenot (jum) <jum@odoo.com>