Bank system

It would be kinda like a second "bag", but you can only access it when talking to a "banker" npc.
By touching the npc, the following thing happens:

your game screen switches to a "bank" element with all stored items in there and by touching an item on your bag, it goes to the bank and vice-versa

• Think about commands involved
• Implement server side behaviours
  • Add Bank class and attach it to player
  • Implement Bank methods (adding item, removing item, sending commands to client, etc)
  • Add Bank npc to world
• Implement client side behaviours
  • Add Bank html element
  • Implement Bank methods (showing items, send correct commands when clicking an item, etc)
• Save and load player data hash (maybe a different hash, leave player data untouched and used only for login, and a new hash for bank, used when the player interacts with a bank)