More Material v1.5.0.0

Two new materials are added to the game: soil and sand.
The material has the same properties as the maize chaff.

Update 1.5.0.0
- Material acquisition was simplified.
- Added pallets with soil and sand.
- Earth and sand textures have been improved.
- New material icons
- Added material information in the menu

Materials can be bought in the shop as a box pallet with soil or sand.

Pallet with soil:
Price: 450 €
Capacity: 2000L

Pallet with sand:
Price: 620 €
Capacity: 2000L