Issue #24283:remove updating of freight from sTaxZoneChanged

It looks like we `update cobmisc` in `sTaxZoneChanged()`, `sTaxDetail()`, and `sFreightChanged()` so `sCalculateTax()` gets the right value. Is there a better way? These `cobmisc` updates are recorded even if the user later cancels without saving.

If we must `update` here, does the same change apply to `sTaxDetail()`?