refactor(group_theory/monoid_localization) remove old_structure_cmd (#9621)
refactor(group_theory/monoid_localization) remove old_structure_cmd (#9621)




Co-authored-by: Scott Morrison <63f04b4d96235eb042cc46d94f14d241d2a26722@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib