feat(DiaryDateActivity): enhance group activity management with duration and order features

- Added `duration`, `durationText`, and `orderId` fields to the GroupActivity model to support detailed activity tracking.
- Updated `addGroupActivity` and `updateGroupActivity` methods in the DiaryDateActivityService to handle new fields, improving activity management capabilities.
- Enhanced the DiaryView component to allow users to input and display duration and duration text for group activities, improving user experience and data clarity.

backend/migrations/20260508_add_duration_and_order_to_group_activity.sql

@@ -0,0 +1,4 @@
+ALTER TABLE `group_activity`
+    ADD COLUMN `duration` INT NULL AFTER `custom_activity`,
+    ADD COLUMN `duration_text` VARCHAR(255) NULL AFTER `duration`,
+    ADD COLUMN `order_id` INT NOT NULL DEFAULT 1 AFTER `duration_text`;