This function plots the length and width lines given an object computed
with analyze_objects(). The function does not call plot.new, so it must
be called after an image is plotted. This can be done either using, e.g.,
plot(img), or analyze_objects(..., plot = TRUE).
This function takes an object computed with analyze_objects() and
plots the length and width lines of each object onto an image. The length
and width lines are calculated based on the position and orientation of the
object, and are plotted using the specified colors and line widths.