GH-98194
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Validate extension JSON: Error: Field 'classes/DisplayServer/methods/file_dialog_show/arguments': size changed value in new API, from 7 to 8.
Validate extension JSON: Error: Field 'classes/DisplayServer/methods/file_dialog_with_options_show/arguments': size changed value in new API, from 9 to 10.

Optional argument added. Compatibility methods registered.
