[scheduler][joy] Add a week view

[flaviendelangle]

Follow up on #17694

By default, the Scheduler should render a styled version of the Time Grid primitive with one column per day of the week.

In this PR:

• Create a WeekView component that renders the current week using the Time Grid primitive
• Render some events (can be hardcoded in the component for now, unless [scheduler][joy] Allow controlling the events used by the component #17702 is merged. If hardcoded, they should still be a flat list that the week view filter and group) inside the grid
• Render the WeekView component by default in the EventCalendar component