Implement legacy source editor survey:
* Force user to switch to cm6 if they haven't seen switch away survey
* Only show user switch away survey if they open ace from another editor
* We need to wait 3 seconds until the survey is being shown
* Add comment to explain the reasoning of not showing cm6 switch away survey for rich text users
* Use localstorage `editor.has_seen_cm6_switch_away_survey` setter to not show the survey if user has seen the survey
* the `editor.has_seen_cm6_switch_away_survey` will have the value `true` even if user is not interacting with it, so update comment to reflect that
* Add `once: true` option to keydown event to avoid unnecessary callback invocation upon key presses
GitOrigin-RevId: c26be2bb39efac2dff112c821fca893e5993dcbf
