Improves tree and ground tile appearance

Refactors tree spawning and rendering:
- Adds seasonal color variations for trees via scripts.
- Introduces `ColorStorage` to manage tree and grass colors
- Removes unused code from tree spawning logic.
- Adjusts ground tile color for better visual appeal.
- Hides debug text on ground tiles.

Entities/GroundTile/ground_tile.gd

@@ -9,6 +9,9 @@ var cell_info: CellDataResource = null
 var spawners_ready: bool = false
 var cached_rng: RandomClass = null
 
+# 326432  229379
+# Grass - 1a7761 1f6051
+
 func _ready() -> void:
 	spawners_ready = true