Feature freeze exception for plasma-sdk - lookandfeelexplorer

[Carl Schwan]

Hi,

I did a large update to lookandfeelexplorer. This improve a bit the visual of the app and modernize the codebase to follow modern practice, but more importantly this fixes the functionality as lookandfeelexplorer was previously still creating metadata.desktop file instead of metadata.json, which made the application with useful in Plasma 5.

MR in question: https://invent.kde.org/plasma/plasma-sdk/-/merge_requests/146

Nico already approved it but this was before I did the metadata.json port, so it would be useful if someone else could take another look.

Cheers,
Carl