Reorganizes and optimizes shared CSS components

Consolidates UI components into a centralized components.css file
Removes duplicate styles across multiple CSS files
Adds utility classes in a new utilities.css file
Reduces overall CSS complexity and improves maintainability

Removes quick-stats.css and redistributes its styles
Updates layout and stylesheet references accordingly

PlanTempus.Application/wwwroot/css/bookings.css

@@ -96,6 +96,7 @@ swp-booking-employee {
   gap: var(--spacing-3);
 }
 
+/* TODO: Consider using swp-avatar.size-xs from components.css instead */
 swp-booking-employee swp-avatar-small {
   width: 24px;
   height: 24px;