refactor(ring_theory/valuation): valuations in `linear_ordered_comm_monoid_with_zero` (#6500)
refactor(ring_theory/valuation): valuations in `linear_ordered_comm_monoid_with_zero` (#6500)

Generalizes the value group in a `valuation` to a `linear_ordered_comm_monoid_with_zero`



Co-authored-by: Aaron Anderson <6a708ae528ec3e8bbcd87cbd53c0d4f4bab63d64@users.noreply.github.com>

leanprover-community/mathlib,leanprover-community/mathlib