Enable dates displayed in RAC Calender that fall outside the current month

[brandonpittman]

Is there a way to make the dates from previous and next months that show up in a calendar enabled?

There's logic in useCalendarState that makes them disabled, but as a convenience, I'd like to let the user click any available date that's visible in the UI.

[LFDanLu]

This is a use case we are tracking here: #3257.