Core path: Add more options

[porg]

Reproduction

1. Create your playlist as needed.
2. Save playlist
3. The save dialog opens
   • Core Path has currently two options
   • - none -
   • C:\LaunchBox\Emulators\RetroArch\cores\*_libretro.dll

Proposal

Add further options:

1. Custom: Filepath containing asterisk.
   • Hint text: Make sure it contains a single asterisk. On export that part will be replaced with the specific Core.

Further options with default filepaths for these app/OS installations:

1. RetroArch on Android
2. RetroArch Plus on Android
3. RetroArch on Windows
4. RetroArch on macOS