[scheduler][joy] Add a day view

[flaviendelangle]

Follow up on #17695.

Allow to render only one day instead of seven.
The code of the week view should be re-used as much as possible.

In this PR:

• Create a DayView component that uses the same internals as the WeekView component but render only one day (with as little code duplication as possible)
• Go to the day view when clicking on a day in the header of the week view

Not in this PR:

• Navigating to other days than the current one
• Switching from one view to another (a basic button to toggle can be added, but the UI to switch in handled in [scheduler][joy] Add navigation between views #17697)
• Render several days at once (this could be a follow up)