Contact update trigger: new has value and is empty modes
The Contact update trigger now offers two additional modes ‑ has value (field changes from empty to filled in) and is empty (field changes from filled in to empty). Both react to the field's value transition, not just the resulting value ‑ a regular change between two filled‑in values (e.g. CZ → SK) will not trigger these modes; the existing any change and matches modes are used for that.