[Fizzlemizz]

Maybe this as a starting point to print the item hyperlink if the bank is open and left shift key is down (doesn't discrimiate the container the clicked item is in but you should be able to determine that using self:GetParent():GetID() as that should be the parent bag/bank slot id.):

local isBankOpen = false
local function ItemHook(self, button)
    if isBankOpen and IsLeftShiftKeyDown() then
        print(C_Container.GetContainerItemInfo(self:GetParent():GetID(), self:GetID()).hyperlink)
    end
end
local frame = CreateFrame("Frame")
frame:RegisterEvent("BANKFRAME_OPENED")
frame:RegisterEvent("BANKFRAME_CLOSED")
frame:SetScript("OnEvent", function(self, event)
    if event == "BANKFRAME_OPENED" then
        isBankOpen = true
    else
        isBankOpen = false
    end
end)
 
hooksecurefunc("ContainerFrameItemButton_OnClick", ItemHook)
hooksecurefunc("ContainerFrameItemButton_OnModifiedClick", ItemHook)

This primarily hooks the functions called by the Blizzard item slots depending on modified state (so maybe you only need one?)