FEAT: Convert status codes to names. (like Pure can)

[MrDowntempo]

The Fish-Pure prompt has one neat feature that Tide seems to be missing. It can translate statuses 129 and up to their signal names. It's described here:
https://pure-fish.github.io/pure/doc/#separate-error-symbol
This would be a nice addition to the status item.

[plttn]

The status item should already do this:

Last login: Tue Apr 28 15:00:43 on ttys000
❯ return 140
~                                                                           ✘ SYS