BigDec operation speedups (backport #8006)

[mergify]

Changes:

• Rename precisionReuse -> defaultBigDecPrecisionReuse
• Rename precisionReuseSDK -> precisionReuseSDKDec
• Use squaredPrecisionReuse properly (saving many internal ops). This is clearly state compat because we are replacing double Mul's with a single one that will commute.
• expose precisionReuse as an argument more consistently
• Remove redundant copies in many BigDec operations
• Speedup common BigDec X Dec ops
  • Just needs tests
• Speedup Quo w/ rounding - Update: My intuition was wrong for roundup, Now looking into RoundDown
  • Truncate was significantly sped up. (Saved the chop routine, and operate on something two word sizes smaller!)

Its easiest to review this PR commit by commit

---

This is an automatic backport of pull request #8006 done by Mergify.

[mergify]

Cherry-pick of b56059e has failed:

On branch mergify/bp/v23.x-iavl-v1/pr-8006
Your branch is up to date with 'origin/v23.x-iavl-v1'.

You are currently cherry-picking commit b56059e4.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   CHANGELOG.md
	modified:   osmomath/decimal.go
	new file:   osmomath/decimal_bench_test.go
	modified:   osmomath/decimal_test.go
	modified:   x/concentrated-liquidity/math/math.go
	modified:   x/concentrated-liquidity/swapstrategy/one_for_zero.go
	modified:   x/gamm/pool-models/stableswap/amm.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod
	both modified:   go.sum
	both modified:   osmomath/go.mod
	both modified:   osmomath/go.sum
	both modified:   osmoutils/go.mod
	both modified:   osmoutils/go.sum
	both modified:   x/epochs/go.mod
	both modified:   x/epochs/go.sum
	both modified:   x/ibc-hooks/go.mod
	both modified:   x/ibc-hooks/go.sum

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally