Change "base" to "station" in docking error messages

[statico-alt]

Several error messages still use "base" instead of "station":

• "You must be docked at a base to perform this action. Use 'dock' at a POI with a base, or use 'get_poi' to check if your current location has a base." → should say "station"
• "No base at this location" → should say "station"

Reported by @jimmcq on Discord