Refactors calendar event rendering and management

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.

wwwroot/css/calendar-base-css.css

@@ -102,7 +102,7 @@ swp-header-cell,
 swp-time-cell,
 swp-day-cell,
 swp-events-container,
-swp-event,
+swp-day-columns swp-event,
 swp-loading-overlay,
 swp-nav-group,
 swp-nav-button,
@@ -117,7 +117,7 @@ swp-date-range,
 swp-day-name,
 swp-day-date,
 swp-event-time,
-swp-event-title,
+swp-day-columns swp-event-title,
 swp-spinner {
   display: block;
 }
@@ -151,11 +151,11 @@ swp-spinner {
 swp-calendar-container,
 swp-calendar-grid,
 swp-day-column,
-swp-event,
-swp-event-group,
+swp-day-columns swp-event,
+swp-day-columns swp-event-group,
 swp-time-axis,
-swp-event-title,
-swp-event-time {
+swp-day-columns swp-event-title,
+swp-day-columns swp-event-time {
   user-select: none;
   -webkit-user-select: none;
   -moz-user-select: none;
@@ -163,8 +163,8 @@ swp-event-time {
 }
 
 /* Enable text selection for events when double-clicked */
-swp-event.text-selectable swp-event-title,
-swp-event.text-selectable swp-event-time {
+swp-day-columns swp-event.text-selectable swp-day-columns swp-event-title,
+swp-day-columns swp-event.text-selectable swp-day-columns swp-event-time {
   user-select: text;
   -webkit-user-select: text;
   -moz-user-select: text;