Add ItemContextMenuClicked Event Support

[wrakocy]

What changed

• Added ItemContextMenuClicked event callback to MudCalendar component
• Created CalendarItemClickEventArgs<T> class to pass both MouseEventArgs and the clicked calendar item
• Implemented context menu handlers in MonthView and DayWeekViewBase
• Added @oncontextmenu:stopPropagation directive to prevent event bubbling
• Added bUnit test to verify new functionality

Why

• Offers users the ability to show context menus when right-clicking on calendar items, similar to the existing CellContextMenuClicked functionality for cells
• Enables actions like editing, deleting, or viewing details of specific calendar items via right-click
• Provides consistent API pattern matching CellContextMenuClicked behavior

Notes

• Breaking changes: None
• API additions:
  • MudCalendar.ItemContextMenuClicked parameter of type EventCallback<CalendarItemClickEventArgs<T>>
  • CalendarItemClickEventArgs<T> class with MouseEventArgs and Item properties
• Works across all calendar views
• Coexists with ItemClicked (both events can be used together)
• Test component demonstrates usage (right-click on calendar items to trigger the event)

Demo 1: Log Both Cell and Item Context Menu Click Events

Cell.and.Item.Events.Demo.mp4

Demo 2: Show Item Context Menu

Item.Context.Menu.Demo.mp4

[danheron]

Thanks!