Tell players about the shop being full/out of stock when they try to sell/buy

[sandtechnology]

Discussed in #1529

^{Originally posted by Andre601 October 31, 2021}
When a player tries to sell or buy an item to/from a shop is QuickShop displays the sell/buy prompt, even if the shop in question has not enough space or items to keep buying or selling them.

Instead of the default sell/buy prompt should QuickShop post a message, telling about the shops current situation and that because of this, the player can't sell or buy to/from it.