core: frontend: extension manager installed extension buttons clipping

[ES-Alexander]

Current behaviour

Expected or desired behaviour

We should either allow the buttons row to wrap, or make it scrollable on overflow, instead of having it just spill over outside the card.

Prerequisites

• [X] I have checked to make sure that a similar request has not already been filed or fixed.

[nicoschmdt]

This seems to be already fixed on the latest master