I cannot find the calendar store in Informant 4.92 and later?
That is correct the calendar store has been removed from Informant 4.92 due to some changes that the calendar content provider had been planning to implement.
You can still add custom calendar content.
To do so please go into the Informant settings, calendars templates, manage calendars, and choose the option to add a new calendar. In the calendar properties select subscribed calendar and the options available for the custom calendar content will be presented. You can select the data that you want to show in the calendar and it will be visible in Informant.
This content cannot be synced between Informant apps, you will need to set each Informant application to be subscribed in the same manor.