editor: Translate utf16 to utf8 offsets in `copy_highlight_json` (#40981)

Fixes ZED-2FM

Release Notes:

- Fixed panic in copy highlight json action
16f7bd0a2eLukas Wirth committed on 10/23/2025, 8:46:50 AM· committed by GitHubparentc529a06
1 file changedLine totals unavailable