mathlib

e0547059 - refactor(topology/metric_space/antilipschitz): generalize to pseudo_metric_space (#6841)

refactor(topology/metric_space/antilipschitz): generalize to pseudo_metric_space (#6841) This is part of a series of PR to introduce semi_normed_group in mathlib. We introduce here anti Lipschitz maps for `pseudo_emetric_space`.