Add support for tab management in active session

[ReDEnergy]

Implement tab management in active session through drag-drop:

• drag-n-drop tabs to re-arrange them
• move tabs from a certain window to another window
  • move to new window if dropped outside a window area?
• add context menu for tabs - reload/pin/unpin/close/move to new window/etc
• optional
  • add toolbar buttons for various actions if needed