1. Use `this.` instead of `{{action}}` where applicable
2. Use `{{fn}}` instead of `@actionParam` where applicable
3. Use non-`@` versions of class/type/tabindex/aria-controls/aria-expanded
4. Remove `btn` class (it's added automatically to all DButtons)
5. Remove `type="button"` (it's the default)
6. Use `concat-class` helper
Recently we started giving admins a notice in the advice panel when their translations have become outdated due to changes in core. However, we didn't include any additional information.
This PR adds more information about the outdated translation inside the site text edit page, together with an option to dismiss the warning.
This is the first of a number of PRs aimed at helping admins manage their translation overrides. It simply adds a list of available interpolation keys below the input field when editing an override.
It also includes custom interpolation key.
Admins can now edit translations in different languages without having to change their locale. We display a warning when there's a fallback language set.
