Implements procedural ground tile generation

Adds procedural ground tile generation with chunking for improved performance.

Includes:
- Ground tile entity with debug text and cell information
- Grass and tree placement based on cell data
- Ground shader for visual representation
- Chunk loading and unloading system based on player position

grass.gdshader

@@ -16,7 +16,7 @@ global uniform float wind_noise_size; // high values dont work well
 global uniform float wind_noise_speed;
 
 // Instance the Player Position through a GDScript in the _physics_process
-instance uniform vec3 player_position;
+global uniform vec3 player_position;
 
 void vertex() {
 	vec3 world_position = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;