Add thirst mod

[archfan7411]

This PR removes thirsty and adds a new thirst mod, thirst, written specifically for Wastelands.

Thirst mechanics overview:

• Thirst depletes one thirst point every 30 seconds, and the HUD bar holds 20 thirst points
• If a player lets their thirst points run out, they will be penalized 3 hitpoints every 30 seconds.
• Standing in ws_core:water_source grants 1 thirst point every 2 seconds

Tools added:

• Filter straw: a cheap and short-lived tool, the straw permits the player to drink tainted water directly. Although it has a very cheap crafting recipe (shapeless, 1 sandy dirt + 1 stick), it breaks very quickly and players will find more advanced options better suited for later play.
• Canteen: A robust and efficient option, the canteen can carry much more water than the filter straw. However, it does not purify the water and must be refilled from clean water.