frontend: Both regular and mini widgets shold be draggable on edit-interface-mode

### Current behaviour

Today, only he mini widgets are draggable in place, what makes the process non-intuitive and degrades the user experience for newcomers.

### Expected or desired behaviour

To keep the UI consistency, a drag-in-place mechanism should be added also to the regular widgets. Even if its added to the center of the screen or to the most empty region.

### Prerequisites

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

Start by locating the edit-interface-mode implementation and the existing drag-in-place handling for mini widgets. Compare how regular widgets are rendered and positioned, then verify that both widget types can be dragged in place without disrupting the interface layout.

Written by the indexing model from the issue text.