Update Info.plist with Tiled file types

[JarvisX-Z]

Fix macOS UTI declarations for Tiled file types
This PR improves macOS file type recognition by properly declaring Uniform Type Identifiers (UTIs).
Changes:
Added LSItemContentTypes for .tmx and .tsx
Added UTExportedTypeDeclarations
Added support for .tsx files (tilesets)
Ensured valid and clean Info.plist structure
Result:
macOS can reliably identify Tiled file types
Double-clicking .tsx files should open correctly
Improves integration with Spotlight and Quick Look

[CelticMinstrel]

Nice! That "conforms to XML" should also let the Finder know that BBEdit can open tmx and tsx files.

I think there were also more file extensions used by the JSON map format? I'm not quite sure; I can't find where I saw those referenced before. Still, recognizing the primary tmx and tsx is already a big improvement.

[JarvisX-Z]

Thanks for the feedback!
Good point about additional file extensions for the JSON map format — I’ll look into that and update the PR if needed.
Also, I don’t currently have access to a macOS environment to test these changes locally. I’ve based the implementation on the documentation and existing patterns, so I’d really appreciate your help with testing on macOS.

[CelticMinstrel]

That might be difficult, unless there's an artifact I can download from the CI or something – I'm not set up to build Tiled at the moment and am probably missing most of the dependencies.