yams #294378 the constraints do not compare properly [validation pending]

e.g. currently SizeConstraint(min=0, max=1) does not compare equal (nor hashes similarly) to an equivalent constraint (where min=0, max=1).

This makes cubicweb (from 3.19) very inefficient at sync_schem(etype) since it uses set membership to compute constraints that must be deleted and new constraints (from fa00fc251d57).

priorityimportant
typebug
done in0.41.0
load0.500
load left0.000
closed by#12acdd74842b [constraints] provide proper comparison and hashability between constraints, #9e0e59671d5f [constraints] provide proper comparison and hashability between constraints
patch[constraints] provide proper comparison and hashability between constraints [applied][constraints] provide proper comparison and hashability between constraints [applied]