Convert calendar controller to use named parameters

[kawaijoe]

For consistency, controllers should use named parameters instead of optional parameters. This is commonly used throughout the flutter library and may prove problematic when we need to accept multiple fields.
https://api.flutter.dev/flutter/widgets/ScrollController/ScrollController.html

For example:

forui/forui/lib/src/widgets/calendar/calendar_controller.dart

Line 51 in 06c6b26

FCalendarMultiValueController([super.value = const {}])