When hovering the number of stars of a course in front-end, for instance,
one can see "4,16666666666667 stars on 5". This is not very convenient.
The number is rounded up to two decimals instead. -> "4,17 stars on 5".
Same fix is done in backend in slides-specific kanban view of ratings. Value
is now rounded.
Finally _rating_get_repartition is fixed round values to the nearest half
value. We generally receive integer values between 0 and 5 but other values
may exist. Getting a repartition rounded at nearest half integer is sufficient
notably when looking at star-based display which covers only complete or half
complete stars.
Task-2728564
Part-of: odoo/odoo#82792
Co-authored-by: Noé Antoine <nan@odoo.com>
Co-authored-by: Thibault Delavallée <tde@odoo.com>
