Is your feature request related to a problem? Please describe.

I'm using ChestShop for Admin Shop and Player shops too. When players want to sell their stuff after farming/mining, they have to spam the selling sign in the Admin Shop to sell all their items.

Describe the solution you'd like

A feature, similar to SHIFT_SELLS_IN_STACKS would nice, for example CTRL_SELLS_ALL. If you allow this, holding the Ctrl key while left clicking the ChestShop sign, one click would enough to sell all the sign's item from your inventory.

Interesting idea although I don't think it's possible to detect ctrl the same way shift is (it's basically detecting that the player is sneaking, you can't really sprint while standing still ;)) Gonna have to think about a good way to add that, maybe with a middle mouse click? Or a setting to change shift in the config to sell all instead of just stacks.

Thank you for adding this option.
Middle mouse click seems good for the additional option, but I see its more difficult because PlayerInteractEvent isnt fired on middle click. My other thoughts was double-click, or double hitting the shift, but these are not easy to implement too.