and for separation of concerns:
The final G-code preview no more uses ExtrusionPaths structure
to hold the G-code path data extracted by parsing the G-code.
Instead, the ExtrusionPath class has been trimmed down back to
the original size before the G-code preview was introduced,
and a new GCodePreviewData::Extrusion::Path class was created to hold
the additional path data as the extruder ID, color change ID
and fan speed.
These firmwares use M135 Tn and M108 Tn commands for changing active tool, which the analyzer did not recognize. The toolpaths were then rendered in wrong color, extruder offset etc. This surfaced in issue https://github.com/prusa3d/PrusaSlicer/issues/2566
Added synchronization of GCodePreviewData between the front end / back end
(GCodePreview data is only used if PrintStep psGCodeExport is finished).
Added reset of GCodePreviewData on Print::apply() to conserve RAM.
