[FIX] (legend extension points) A recent regression. The indexes of the legend extension points, for the several colorAxis/dataCell, (legendDot_, legend2Dot_, etc) were not being correctly assigned.
[FEAT] (legend extension points) Ability to specify legend$Dot_ or legend$Rule_ to affect any legend group (1, 2 , 3...).
Some more work is needed to provide the same legend group extension points separation to the legendPanel_, legendMarkerPanel_ and legendLabel_.