REGRESS: Remove translateMetrics() from LTMPlot

This is a regression to remove the metric translation
functionality from LTMPlot.

WE WILL REINTRODUCE BEFORE RELEASE!

It has been regressed because;

1. It crashes on QT5 with Win32

2. It has significant performance penalties;

   It really should not instantiate an LTMTool object
   (Ale did discuss this with me and I gave it the go
   ahead, so my bad).

3. It should be executed on applySettings() not on
   each refreshPlot().

4. It has a bug regarding uunits being lost and breaking
   sharing of a common axis.