Addresses inconsistent time formatting and lack of timezone
handling throughout the application by introducing a
`TimeFormatter` utility.
This class centralizes time formatting logic, providing
timezone conversion (defaults to Europe/Copenhagen) and
support for both 12-hour and 24-hour formats, configurable
via `CalendarConfig`.
It also updates event rendering to utilize the new
`TimeFormatter` for consistent time displays.
Improves code organization and maintainability by separating concerns related to all-day event rendering, header management, and event resizing.
Moves all-day event rendering logic into a dedicated `AllDayEventRenderer` class, utilizing the factory pattern for event element creation.
Refactors `AllDayManager` to handle all-day row height animations, separated from `HeaderManager`.
Removes the `ResizeManager` and related functionality.
These changes aim to reduce code duplication, improve testability, and enhance the overall architecture of the calendar component.
