Fix incorrect special fp number handling in min/max reduction

Neither Eigen nor c++ stdlib have well defined min/max handling to match
Tosa spec and frameworks such as TF. for instance:
  reduce_min([4, float('nan')]) -> float('nan')
  reduce_min([float('nan'), float('nan')]) -> float('nan')
  reduce_min([float('-inf'), float('inf')]) -> float('-inf')

This patch creates custom floating point reducer for min/max, and create
framework tests to verify special floating point min/max reduction.

Co-authored-by: Eirini Vlassi Pandi <eirini.vlassipandi@arm.com>

Change-Id: If59d3ebd937ce46615a8da35a535338a94be1d3f
Signed-off-by: TatWai Chong <tatwai.chong@arm.com>