BUG : Zero stock amount item - adding to Vault

[tomik-z-cech]

Describe the bug :
It is possible to add item that's not in stock to Vault.

To Reproduce :

• Navigate to shop
• Find item that's not in stock
• Add the item to Vault
• Navigate to Vault
• See Vault content

Expected behavior :
Item that is not in stock cannot be added to Vault.

Screenshots :
N/A

Devices :
All devices.

Additional context :
Possible insufficient defense programming.

[tomik-z-cech]

Quantity adding input field and "Add to Vault" button displayed only if item is in stock, {% if item.item_stock > 0 %} added to item_detail.html template.

Bug fixed in commit 28df137.