## About The Pull Request
This PR adds a **persistent** piggy bank to the station vault that,
while it can hold up to 3300 credits carried between shifts. However,
you can only insert up to 1600 (on top of the 50 creds it
auto-generates) each shift, so it does take a small, itsy bitsy of
patience to fill it to the brim.
## Why It's Good For The Game
I put some effort coding persistent piggy banks when making the
cafeteria PR for the museum away mission a while ago (which apparently
isn't enabled yet because the key holders forgot to ig). It'd be a shame
of all the existing code were only used for a single persistent piggy
bank.
610cf3681a