Remove docking widget top right controls

The 3 controls on the top right of each view are useless and cluttering the whole UI (3 controls times the number of views on the screen).

The controls are:

1. Drop down that lists the grouped tabs: useless as one can directly see the tabs on screen.
2. Undock button: user can intuitively just drag the tab to dock/undock
3. Close button: tabs already have close buttons. Also this close button closed the whole group which is both unintuitive and hardly needed.