Add "ShowTrack" function to live's m4l track object

[Tukishiro_Hikari]

Show a track into the view.
If it's not in the view then scroll the view (arrangement or session) to make the track into the view (and can be seen by user)

This will make navigating a large project possible by using custom m4l patches or controllers.
and it will be far more efficient than show/hide tracks.

Thanks!!