Add support for Sortix in essential types

[sideeffect42]

I couldn't hold myself back from adding support for the Sortix hobby OS.

There's two issues still left (those are bugs and unimplemented features on Sortix' side):

• explorer/memory:
  • The %.f format isn't implemented
• explorer/{disks,interfaces}:
  • disked/ifconfig fail when trying to open /dev/tty over a non-interactive SSH session; a workaround is to use ssh -tt
• type/__file:
  • there is no cksum(1) so the cksum explorer fails; a workaround is to install a Python-based cksum replacement manually.
  • I needed to add a workaround in the stat explorer until Sortix' ls(1) supports -n

[4nd3r]

Noice.

But this review will take some time, because I want to actually try it out first...

[sideeffect42]

But this review will take some time, because I want to actually try it out first...

No hurry, it's a just for the lulz PR.