This PR change generic calendar view to make it behave more like
google calendar.
These changes includes :
- Scss rules for small event(<15 minutes) so that the title is always readable.
On top of that, the top border of a darker color has been removed
for these even to allow more space.
- Event longer than 24h are now shown in the all day column independent
of their 'allday' status
- Time is now added in the event description, if the event is
shorter than 30 minutes, only the start time is displayed at the end
of the line.
If the event is longer, the start time and end time are displayed
on a new line.
task-id : 3114155
closesodoo/odoo#109736
Signed-off-by: Michaël Mattiello <mcm@odoo.com>