CalendarEventDayId in FactK12AcademicCalendarEvents needs to be defined as foreign key

[CJ-Gilbert-CEPI]

Describe the bug
In the code for FactK12AcademicCalendarEvents, the field for CalendarEventDayId (which should point to DimCalendarEventDays) is not defined as a foreign key so in diagrams it makes it look like DimCalendarDays is just hanging out by itself..

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NOTE: Please do not confuse CalendarEventDateId (which goes to DimDates and is defined as a foreign key) with
CalendarEventDayId which is what needs to be fixed.