Improve imports UX

[odrling]

When importing a karaoke we call the kara.moe from the UI to show some information.
Previously it showed the karaoke file name from Mugen which worked fine. Now instead of calling the kara.moe API from the UI we should just ask karaberus which already does the same on import and show the regular UI for karaokes in karaberus with what karaberus will use after import.