Add a way to collect sap from Birch trees using an Iron Tap

.

Technical Details:

Collection: Use an Iron Ingot to craft a "Tap". When placed on a Birch log, it fills a glass bottle over time.

Availability: Sap only flows in cold/temperate biomes. It is not infinite.

Function: Drinking Birch Sap removes "Poison" and "Nausea" effects.

Hardcore Balance: If you collect too much from one tree, it dies (leaves disappear).

Why it's needed: Currently, Birch is the most useless wood. This gives players a reason to find Birch forests for survival and medical needs, especially when dealing with poisonous plants or food. It’s a grounded, realistic addition that fits the survival theme