Experiment with alternate definition of dominant pole

[pganguli]

We currently treat the pole farthest from the origin as the dominant pole:

TimingDebug.jl/src/utils.jl

Lines 22 to 27 in f8ac4e3

	"""
	dominant_pole(poles)
	Find the dominant pole out of poles `ps`.
	"""
	dominant_pole(ps::Vector{<:Complex}) = argmax(abs, ps)

We should try working out some alternative definitions as we discussed earlier.