tor/changes/ticket32088

  o Major features (Proposal 310, performance + security):
    - Implements Proposal 310 - Bandaid on guard selection.
      Proposal 310 solves a load-balancing issue within Prop271 which strongly
      impact experimental research with Shadow.
      Security improvement: Proposal 310 prevents any newly Guard relay to
      have a chance to get into the primary list of older Tor clients,
      except if the N first sampled guards of these clients are unreachable.
      Implements recommendation from 32088.
      
      Proposal 310 is linked to the CLAPS project researching optimal
      client location-aware path selections. This project is a collaboration
      between the UCLouvain Crypto Group, the U.S. Naval Research Laboratory and
      Princeton University.