Issue Summary

While trying to view calendars in a space, Team Calendar will trigger a GET /rest/calendar-services/1.0/calendar/subcalendars.json?calendarContext=spaceCalendars&viewingSpaceKey=<space-key> request to retrieve calendar's data, then populate the data in the payload onto the UI.

This endpoint currently does not have pagination, TC will try to display all the calendars in the space.

The lack of pagination creates a scaling issues because it will take a long time to load as the payload grow larger.

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Create a space
2. Create calendars in the space
3. Load time will gradually increase as more and more calendar gets created over time.
   Through support cases, with a space consists of ~400 calendars, the subcalendars.json will take about 3 minutes to load.

Expected Results

Team Calendar should provide an option to paginate data to avoid loading everything in one go.

Actual Results

Team Calendar loads all calendars in the space.

Workaround

Move a subset of the calendars over to a seperate space to reduce overall load time.
Please note that this is NOT to migrate the actual calendars to another space but just the 'view' of it.

1. Create a new space (or take note of the destination space key)
2. Shut down Confluence
3. Backup the Confluence database.
4. With calendar name and the source space key as the search clauses, execute the query below to locate the <calendar-id>:

   SELECT ID FROM AO_950DC3_TC_SUBCALS WHERE "NAME"='<calendar-name>' AND "SPACE_KEY"='<source-space-key>'
   

5. Execute the query below to move the calendar view to the destination space:

   UPDATE AO_950DC3_TC_SUBCALS_IN_SPACE SET SPACE_KEY='<destination-space-key>' WHERE SUB_CALENDAR_ID='<calendar-id>';