Add context for item "basin"

[Aloxaf]

Summary

SUMMARY: None

Purpose of change

The item "basin" and terrain "basin" should in different context.

Describe the solution

Add context for item "basin".

Describe alternatives you've considered

Add context for terrain "basin" or both of them.

Testing

Ran lang/update_pot.sh and checked cataclysm-dda.pot

#: lang/json/CONTAINER_from_json.py
msgctxt "container"
msgid "basin"
msgid_plural "basins"
msgstr[0] ""
msgstr[1] ""

#: lang/json/overmap_terrain_from_json.py
msgid "basin"
msgstr ""

Additional context

Cataclysm-DDA/data/mods/Aftershock/items/items.json

Line 27 in 3166271

"name": "basin",

Cataclysm-DDA/data/json/overmap/overmap_terrain/overmap_terrain.json

Line 721 in 3166271

"name": "basin",