[Backport to 11.1] Click on 'plus' button of container throws JS error

While adding a new component, all containers show a '+' button when hovered. Clicking a container adds the component to that container. However, when you click on the '+' button a JS error is thrown and the component is not added.

Steps to reproduce:
1. edit a channel
2. select a component in the catalog to add
3. hover over a container and click on the '+' button that appears

Expected: the component is added to the container
Actual: the component is not added and a JavaScript error is logged:

Uncaught TypeError: Cannot read property 'getId' of undefined
    at t.value (app-3848566….js:8)
    at e.value (app-3848566….js:5)
    at e.value (app-3848566….js:5)
    at HTMLDivElement.<anonymous> (app-3848566….js:5)
    at HTMLDivElement.dispatch (vendor-3848566….js:97)
    at HTMLDivElement.g.handle (vendor-3848566….js:97)