Better inventory UI

[LoicCK]

The inventory UI is very simple for now. It is just a list of item on the right of the screen. This is not a good implementation for many reasons.

The goal would be to add a new inventory screen, on the base of what is done for the options screen.

• Decide how to implement it
• Decide if a redesign of the core inventory system is needed or not
• Decide on how the screen will work
• Design the screen with the new UI Make a better UI in-game #3
• Add options for the user with a given item (use it, destroy it...)
• Implement the final screen in the game screen