Automatically localise desktop UI text from project resources

Allow developers to connect desktop UI text directly to project localisation keys in Studio, without writing repetitive assignments in each window's Opening handler.

The Inspector should offer a choice between literal text and a localisation resource, with a searchable key picker and translated preview. Cover window titles, control captions, tooltips, placeholder text, menu and toolbar captions, tab titles, and list column headings. Existing literal text must continue to work unchanged.

Provide an application UI locale so an app can offer a language preference. Changing it should refresh existing localised UI and determine the language of newly created windows. Explicit Localise() calls remain available for dynamic messages and parameter substitution. Missing translations should use the existing project fallback rules.

An optional :localise:msg.Save shorthand in the designer could select a resource reference; developers should not need to remember this syntax to use the feature.