When user hover the Xref string of a terminal, the string color change
to blue to advise user the xref is clickable. Double click on the blue
Xref go the folio of the terminal and zoom the view to the terminal.
Move RealTerminal class in a new file
Move PhysicalTerminal class in a new file.
Remove the use of QWeakPointer and use instead QSharedPointer
in a big part of the revamp.
