[Mapping - Boxstation] Removed all the POS

The item itself is roughly unfinished. Might re-add after we revamp the economy.
Crewmembers need more ways to earn money before we give them more tools to spend it.

That aside, I haven't seen anyone even try to use them since the week where they got added, and I remember them causing massive shit storms and RP vs Powergaming wars.