Enable updating of Items

[Sylvie]

Some items like shields (or maybe STMR) will be upgraded in-game. The console should allow updating the Objets in the DB.

[Sylvie]

Steps

• [x] Implement Item comparison
• [x] Display panel for modifying the Item if the DM and DB versions differ
• [x] Add method to push the Item with PUT
• [x] Implement Item update in backend