Enhancement: Enable dragging Files from top of sidebar

[yaira2]

Is your feature request related to a problem? Please describe.
Currently, the drag area is limited to the right of the tabs, however, users can't drag the window from the top of the sidebar. This can be confusing, since users expect to be able to drag from any blank spot on the title bar.

Describe the solution you'd like
Extend the drag over the sidebar.