Allow customization of Jira issues in Team Calendars

There's already a Server request for this; we'd love to see it in Cloud.

We use calendars in Confluence for a lot of different things, but one of them is to display Jira issues from our vacation request project. We cannot force the user to include their name in the summary field, so I'd really like it if we could customize which fields display in a given Confluence calendar, so we could include Reporter instead of Summary for this particular project's calendar.