fix: #3626667 Add the schema of the media source and tidy the Feature displays (!9) · Merge requests · project / gherkin

Configuration inspector reported the Feature media type and its two displays.

Add the configuration schema of the Gherkin Script media source.
Drop the lists of themes and syntaxes of the Ace editor from the displays: they are the options of its settings form, not settings of a display.
An update function tidies the displays of installed sites.
The tests sign in by the id of the fields, and open the page of a media item after the site turned it on.

AI-Generated: Yes

fix: #3626667 Add the schema of the media source and tidy the Feature displays