BankItems v30100 now includes LDB support directly. As such this mod is no longer needed once you upgrade to this version of BankItems or above.
BankItemsToggle is a very small LibDataBroker based addon that does pretty much exactly what the names says. It toggles BankItems and BankItems Guild Bank open and closed.
Left-click to toggle BankItems
Right-Click to toggle BankItems Guild Bank