Report Missing Birthdays in Check-ins Birthday report

[AndrewBarbaglia]

Is your feature request related to a problem? Please describe.
B

Describe the solution you'd like
When clicking on the birthday report, being able to toggle a section to list any birthdays that might be missing (i.e. team members who have no birthdays entered in on Check-ins.)

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context