* refactor/test: improve DecApproxEq, fix misuse in mint hooks, create osmoassert package

* revert osmomath accidental rename

* revert osmomath

(cherry picked from commit 91141514)

# Conflicts:
#	osmomath/math_test.go
#	osmoutils/dec_helper.go
#	osmoutils/test_helpers.go
#	x/gamm/pool-models/internal/test_helpers/test_helpers.go
#	x/gamm/pool-models/stableswap/amm_test.go
#	x/gamm/twap/api_test.go
#	x/gamm/twap/logic_test.go
#	x/gamm/twap/types/utils_test.go