Create new membership status for deceased members - In Memorium

[sarahjonesmilligan]

Board meeting 262: please add a inactive membership status of "In Memorium", because it feels weird to say Sam withdrew when he died with an active membership. It otherwise behaves the same as withdrawn though.

[azend]

Adding a new membership status should be as simple as adding one to the config. But I'll have to further review the codebase to evaluate if there are any issues regarding how statuses are handled re: business rules.

https://github.com/kwartzlab/kos-base/blob/main/config/kwartzlabos.php#L47